UNIVERSITY   OF   CALIFOl.  'TA    PUBLICATIONS. 


COLLEGE  OF  AGRICULTURE. 


AGRICULTURAL  EXPERIMENT  STATION. 


ASPARAGUS  AND  ASPARAGUS  RUST 
IN  CALIFORNIA. 


By  RALPH  E.  SMITH. 


BULLETIN    No.    165. 

(Berkeley,  Cal.,  January,  1905.) 


SACRAMENTO: 
w.  w.  shannon,    :::::::   superintendent  state  printing. 

1905. 


BENJAMIN  IDE  WHEELER,  Ph.D.,  LL.D.,  President  of  the  University. 

EXPERIMENT  STATION  STAFF. 

E.  W.  HILGARD,  Ph.D.,  LL.D.,  Director  and  Chemist. 

E.  J.  WICKSON,  M.A.,  Horticulturist. 

W.  A.  SETCHELL,  Ph.D.,  Botanist. 

ELWOOD  MEAD,  M.S.,  C.E.,  Irrigation  Engineer. 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

R.  H.  LOUGHRIDGE,  Ph.D.,  Agricultural  Geologist  and  Soil  Physicist.    (Soils  and  Alkali.) 

M.  E.  JAFFA,  M.S.,  Assistant  Chemist.    (Foods,  Nutrition.) 

G.  W.  SHAW,  M.A.,  Ph.D.,  Assistant  Chemist.    (Starches,  Oils,  Beet-Sugar.) 

GEORGE  E.  COLBY,  M.S.,  Assistant  Chemist.    (Fruits,  Waters,  Insecticides.) 

RALPH  E.  SMITH,  B.S.,  Plant  Pathologist. 

A.  R.  WARD,  B.S.A.,  D.V.M.,  Veterinarian,  Bacteriologist. 

E.  W.  MAJOR,  B.Agr.,  Animal  Industry. 

A.  V.  STUBENRAUCH,  M.S.,  Assistant  Horticulturist,  in  charge  of  Substations. 

E.  H.  TWIGHT,  B.Sc,  Diplome  E.A.M.,    Viticulturist. 

F.  T.  BIOLETTI,  M.S.,    Viticulturist. 

WARREN  T.  CLARKE,  B.S.,  Assistant  Field  Entomologist. 

H.  M.  HALL,  M.S.,  Assistant  Botanist. 

H.  J.  QUAYLE,  A.B.,  Assistant  Entomologist. 

GEORGE  ROBERTS,  M.S.,  Assistant  Chemist,  in  charge  Fertilizer  Control. 

C.  M.  HARING,  D.V.M.,  Assistant  Veterinarian  and  Bacteriologist. 

C.  A.  COLMORE,  B.S.,  Clerk  to  the  Director. 


R.  E.  MANSELL,  Foreman  of  Central  Station  Grounds. 

JOHN  TUOHY,  Patron,  )   _  , 

y  Tulare  Substation,  Tulare. 
JULIUS  FORRER,  Foreman,  ) 

J.  E.  McCOMAS,  Patron,  Pomona,  >. 

J.  W.  MILLS,  Superintendent,  Pomona, 

m     .  „  „         .  ,  „    ^        „,.„..       >    Southern  California  Substation. 

In  charge  Cooperation  Experiments  of  Southern  California, 

JOHN  H.  BARBER,  Assistant  Superintendent,  Ontario, 

J.  W.  ROPER,  Patron, 

HENRY  WIGHTMAN,  In  charge 

ROY  JONES,  Patron, 


V  University  Forestry  Station,  Chico. 


,    University  Forestry  Station,  Santa  Monica. 
WM.  SHUTT,  Foreman,    \ 

H.  O.  WOODWORTH,  M.S.,  Foreman  of  Poultry  Station,  Petaluma. 


The  Station  publications  (Reports  and  Bulletins),  so  long  as  avail- 
able, will  be  sent  to  any  citizen  of  the  State  on  application. 


CONTENTS. 


Page. 

INTRODUCTION 5 

Acknowledgments 5 

Results  Achieved 7 

ASPARAGUS  IN  CALIFORNIA 7 

THE  ASPARAGUS  PLANT 12 

CULTURE  OF  ASPARAGUS 13 

THE  ASPARAGUS  RUST 18 

History  of  the  Disease  in  California 20 

Nature  of  the  Rust 21 

Cause 23 

The  Mycelium 24 

Effect  on  cells  and  tissues 25 

Spore  Forms  of  Puccinia  asparagi 27 

Spring  rust  stage 27 

Red  rust  stage ;  germination;  distribution;  conditions  affecting  germination..  27 

The  black  rust  stage 35 

Nature  of  the  Injury  Caused  by  Rust 42 

Amount  of  Loss 45 

Yearly  Life-History  of  the  Rust  Fungus  47 

Relation  of  Natural  Conditions  to  the  Rust 51 

Climatic  and  soil  influences 51 

Soil  Cultivation 58 

THE  PREVENTION  OR  CONTROL  OF  ASPARAGUS  RUST . 59 

Previous  Attempts  at  Asparagus-Rust  Prevention 60 

Spraying  and  similar  methods 60 

Work  in  California 62 

Bordeaux  mixture,  etc. _  62 

Dry  powder  applications _ 64 

Results  of  dry  treatment  in  1903 65 

Work  at  Sacramento  in  1904 68 

Work  at  Milpitas  in  1904 72 

Liquid  spray  experiments  in  1904 77 

General  Conclusions  on  Spraying  and  Similar  Methods  of  Treatment 80 

Dry  sulfur  treatment;  time,  amount,  methods  and  cost 80 

Liquid  spraying;  time  and  methods 84 

Cultural  Methods  and  Location  in  Relation  to  Rust-Control 89 

RUST  PARASITES 91 

VARIETIES  OF  ASPARAGUS 94 

INSECTS  AFFECTING  THE  ASPARAGUS  PLANT 96 

LIST  OF  SUBSCRIBERS 97 

DIRECTIONS  FOR  ASPARAGUS  RUST  CONTROL 98 


ASPARAGUS  AND  ASPARAGUS  RUST  IN  CALIFORNIA. 

By  RALPH  E.  SMITH. 


The  present  bulletin  represents  primarily  a  report  to  certain  aspar- 
agus growers,  canners  and  dealers  of  San  Francisco,  Sacramento,  and 
adjoining  territory,  who  provided  a  fund  of  $2,500  for  the  support  of 
an  investigation  of  the  asparagus  rust,  a  disease  which  seriously 
threatened  to  destroy  or  greatly  injure  their  industry.  The  circum- 
stances under  which  this  investigation  was  undertaken  are  interesting 
and  unique.  Knowing  from  its  history  in  the  East  the  destructive 
nature  of  the  rust,  the  asparagus  interests,  on  its  appearance  in  this 
State,  appealed  to  the  University  of  California  for  aid  in  suppressing 
this  pest.  The  University  had  no  funds  or  men  available  at  the  time 
for  such  a  purpose,  and,  a  bill  having  failed  to  pass  the  Legislature, 
those  most  directly  interested  took  the  matter  into  their  own  hands, 
and  the  California  Fruit  Canners'  Association,  a  leader  in  the  move- 
ment, guaranteed  to  raise  and  turn  over  to  the  University  the  sum 
above  mentioned  if  the  work  should  be  undertaken.  Under  these  cir- 
cumstances the  writer,  having  had  previous  experience  in  the  matter, 
was  called  from  the  Massachusetts  Agricultural  College  to  take  up  the 
work,  which  has  now  extended  over  two  seasons  and  may  be  considered 
as  practically  completed  in  its  main  features.  While  no  sensational 
discoveries  have  been  made,  the  difficult  problem  of  protecting  the 
plant  from  rust  may  be  regarded  as  solved  to  a  very  satisfactory  extent, 
and  it  is  believed  that  the  best  growers  will  continue  to  produce  aspara- 
gus successfully  and  profitably,  which  could  not  be  done  with  the  rust 
unchecked. 

Acknowledgments. — Acknowledgment  for  the  results  achieved  is  due 
primarily  to  all  those  who  aided  financially  in  starting  the  work.  As 
leaders  in  this  portion  of  the  undertaking  must  be  mentioned  Mr. 
William  Boots,  Jr.,  one  of  the  first  growers  to  realize  the  necessity  of 
action,  and  Mr.  R.  I.  Bentley,  General  Manager  of  the  California  Fruit 
Canners'  Association,  who  has  been  most  active  in  promoting  and 
encouraging  the  investigation.  The  money  raised  came  from  the 
growers  in  the  vicinity  of  Milpitas,  Alviso,  and  San  Jose,  those  at 
Sacramento,  many  of  the  large  growers  in  the  river  and  island  dis- 
trict, the  canning  company  mentioned  above,  together  with  the  two 


b  UNIVERSITY    OF    CALIFORNIA  — EXPERIMENT    STATION. 

other  principal  asparagus  canners,  the  Hickmott  Asparagus  Canning 
Company  and  the  Golden  State  Asparagus  Company,  and  from  sub- 
scriptions by  a  number  of  commission  houses  in  San  Francisco.  To 
these  gentlemen  the  credit  belongs  of  starting  and  supporting  the 
investigation. 

In  carrying  on  the  work  the  writer  has  been  given  every  assistance 
by  all  with  whom  he  has  come  into  contact,  and  must  acknowledge  the 
hearty  cooperation  of  the  various  growers  and  canners  in  the  different 
districts  in  carrying  on  practical  studies  and  experiments,  furnishing 
accommodations,  transportation,  etc.,  and  providing  supplies,  appli- 
ances, labor,  and  similar  items.  Experimental  work  in  the  field  has 
been  carried  on  at  the  following  places,  but  the  publication  of  such  a 
list  is  almost  an  injustice  to  many  others  who  were  equally  ready  to 
assist  had  they  been  called  upon. 

The  bulk  of  the  whole  work  has  been  performed  at  the  Boots  ranch 
near  San  Jose  in  conjunction  with  Mr.  William  Boots,  Jr.,  whose  con- 
tinual cooperation  and  assistance  the  writer  wishes  to  fully  acknowl- 
edge. Messrs.  John  Meads,  George  Nicholson,  and  Fred  Cottle  of  the 
same  district  carried  on  various  parts  of  the  work  in  1903.  Similar 
work  was  done  at  the  same  time  with  the  Hickmott  Asparagus  Canning 
Company  at  their  Bouldin  Island  establishment,  Mr.  E.  A.  Schultz  of 
this  company  being  one  of  the  most  active  of  those  interested  in  the 
problem.  In  1904  new  work  was  carried  on  at  Mr.  P.  J.  Van  Loben 
Sels  's  ranch  at  Vorden,  where  every  facility  was  furnished  by  the 
proprietor  to  make  the  undertaking  a  success.  Valuable  information 
was  also  obtained  from  the  practical  work  carried  on  by  most  of  the 
Sacramento  and  Milpitas  growers  in  testing  the  methods  recommended 
for  trial  in  preventing  the  rust.  Among  these  were,  Mrs.  M.  M. 
Harding,  E.  Rider,  O'Brien  Brothers2  Jacob  Olsen,  John  Giusto,  and 
C.  Girolami  of  Sacramento,  and  R.  S.  Barber,  H.  H.  Cropley,  M.  Bellew, 
Henry  Abel,  and  George  Murphy  of  Milpitas.  Besides  these  growers 
and  others  already  mentioned  the  writer  can  not  refrain  from  acknowl- 
edging the  active  interest  in  the  work  shown  by  Messrs.  Hodges,  Gaum, 
and  A.  L.  Smith  of  the  California  Fruit  Canners'  Association,  Messrs. 
Robert  Hickmott  and  his  associates  in  the  company  already  mentioned, 
Capt.  E.  H.  Nielsen  and  Mr.  N.  Goetjen  of  the  Golden  State  Company, 
Messrs.  Jongeneel  and  Bromage  of  the  Vorden  Ranch,  Mr.  G.  Oulton 
of  Twitchell  Island,  and  Mr.  J.  W.  Nelson,  now  of  Hunt  Brothers  Com- 
pany. The  Southern  Pacific  Company,  by  ita  generous  policy  in 
matters  of  transportation  has  also  aided  materially  in  the  work.  Still 
further  mention  may  be  appropriately  made  of  Messrs.  Frank 
Wheeler  of  Concord,  Mass.,  Wm.  Conover  of  Middletown,  N.  J.,  Donner 
Brothers  of  Seabrook,  S.  C,  and  P.  A.  Bonvallet  of  Wichert,  111.,  all  of 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  7 

whom  have  rendered  assistance  in  various  ways.  To  a  host  of  other 
growers, .  canners,  and  handlers  of  asparagus  in  many  different  States 
the  writer  is  indebted  for  information  and  assistance. 

During  the  two  seasons  covered  by  the  investigation  most  of  the 
writer's  time  has  been  spent  in  the  various  asparagus  districts,  and  he 
has  also  had  opportunity  to  supplement  previous  observations  by  trips 
through  the  Eastern  asparagus  centers  in  1903  and  1904. 

Two  publications  have  been  issued  in  connection  with  the  work :  Cir- 
cular No.  9  of  this  Station,  ' '  Report  on  Asparagus  Rust  Investigation, ' ' 
and  a  more  technical  article  in  the  Botanical  Gazette,  July  1904,  on 
"The  Water  Relation  of  Puccinia  Asparagi." 

Results  Achieved. — The  most  valuable  results  achieved,  as  will 
appear  in  the  following  discussion,  may  be  briefly  stated  as  follows: 

The  discovery  of  climatic  conditions  peculiarly  favorable  to  rust 
suppression  in  the  greatest  asparagus-producing  region  of  the  State. 

The  determination  of  the  best  cultural  and  other  means  for  taking 
advantage  of  such  conditions. 

Other  cultural  methods  found  effective  in  keeping  down  the  disease. 

A  test  of  many  methods  of  treatment  by  spraying  and  similar 
operations. 

The  discovery  of  the  peculiar  effectiveness  of  sulfur,  when  properly 
applied,  in  treating  the  rust  in  California. 

Determination  of  the  best  methods,  time,  etc.,  for  applying  sulfur 
and  the  development  of  special  appliances  and  machinery  for  the 
purpose. 

The  discovery  and  study  of  an  active  parasite  upon  the  rust  fungus. 

The  determination  of  comparative  resistance  to  the  rust  of  the 
various  varieties  of  asparagus,  importation  of  varieties  not  obtainable 
in  this  country,  and  the  commencement  of  breeding* experiments  for 
the  production  of  new  varieties,  rust-resistant  and  otherwise  desirable. 

Study  of  the  problem  under  the  local  conditions  of  all  parts  of  the 
principal  asparagus-producing  region,  and  adaptation  of  the  results  to 
each  locality. 

ASPARAGUS  IN  CALIFORNIA. 

The  extent  and  importance  of  the  asparagus  industry  in  California 
is  little  realized  outside  the  circles  of  those  connected  with  the 
business.  The  crop  is  looked  upon  by  many  as  a  pleasant  luxury,  grown 
in  certain  suitable  localities  for  supplying  the  city  markets  in  spring. 
The  fact  is  that  the  city  markets  take  but  a  small  portion  of  the  aspar- 
agus produced  in  the  State,  and,  to  a  large  extent,  the  poorer  quality 
at  that.  The  business  proper  has  quite  a  different  object  than  supply- 
ing such  markets. 


8 


UNIVERSITY   OF    CALIFORNIA— EXPERIMENT    STATION. 


Asparagus  has  been  produced  in  California  for  many  years.  A  small 
field  is  still  in  existence  in  Sacramento  which  is  known  to  have  been 
planted  in  1852,  while  in  the  vicinity  of  San  Jose  the  crop  was  also 
grown  at  an  early  period.     In  its  present  condition  the  business  is  of 


Fig.  1.    Cannery  No.  2.    Hickmott  Asparagus  Canning  Co.,  Bouldin  Island. 

recent  origin,  mostly  the  growth  of  less  than  ten  years,  and  has  come 
into  existence  through  the  development  of  asparagus  canning  and  the 
rapidly  increasing  demand  for  the  product.  Canning  of  asparagus 
on  a  commercial  basis  has  been  practiced  for  only  a  few  years  in  Cali- 


FlG.  2.    Cannery  No.  3.    Hickmott  Company,  Bouldin  Island.     , 

fornia.  Considerable  difficulty  was  experienced  at  first  in  putting  up 
the  vegetable  with  uniform  success,  and  as  the  market  for  any  con- 
siderable amount  of  canned  asparagus  was  entirely  undeveloped  in 
the  early  history  of  the  business,  conditions,  even  as  late  as  ten  years 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  \) 

ago,  gave  little  indication  of  the  development  of  any  such 
industry  as  now  exists.  The  business,  when  once  established, 
proving    to    be    very    profitable,     both    to    producer     and     canner, 


• '  -."  — 

•  ^a       j^^2|^i4<4Ji2i^^£r3                        ^BI-^^MB^^^^^^^ 

';;;  ^                               MPf      i 

wife.  * 

K                            I 

f  '                 l^^^-^^^at^MBJI 

Fig.  3.    Milpitas  cannery.    California  Fruit  Canners'  Association. 
Enlarged  in  1905. 

large  plantings  of  the  vegetable  were  made,  and  up  to  1902  the  acreage 
increased  enormously.  Meantime  the  rust  disease  had  crippled  the 
canning  of  asparagus  in  other  parts  of  the  country,  located  principally 


Fig.  4.    Sacramento  cannery.    California  Fruit  Canners'  Association. 
Rebuilt  in  1905. 

on  Long  Island  and  in  New  Jersey,  and  with  the  greatly  increased 
demand  for  canned  asparagus  the  planting  of  the  crop  enjoyed  quite 
a  boom  in  California,     This  new  planting  took  place  principally  in  the 


10 


UNIVERSITY    OF    CALIFORNIA— EXPERIMENT    STATION. 


delta  country  between  Sacramento,  Stockton  and  Port  Costa,  at  the 
junction  of  the  Sacramento  and  San  Joaquin  rivers,  where  the  peaty 
and  sedimentary  soils,  after  reclamation  by  levees  and  pump  drain- 
age, proved  especially  suited  for  the  production  of  canning  asparagus. 
In  1903  there  was  nearly  6,000  acres  of  asparagus  in  this  section.  The 
leader  in  this  development  was  the  Hickmott  Asparagus  Canning  Com- 
pany, and  to  Mr.  Robert  Hickmott  belongs  much  of  the  credit  for  the 
present  popularity  of  canned  asparagus.  With  great  confidence  as 
to  the  future  of  the  business  he  went  ahead  at  Bouldin  Island,  contract- 
ing for  the  planting  of  an  enormous  acreage  and  building  canneries  to 
handle  the  product.  This  company's  two  large  canneries  on  the  island, 
used   exclusively   for   asparagus,   are  shown   in  Figs.   1   and   2.     The 


Fig.  5.    Vordcn  eannerv.    California  Fruit  Canners'  Association. 


flooding  of  Bouldin  Island  in  the  spring  of  1904  and  consequent 
crippling  of  the  business  was  a  distinct  calamity  to  California. 

Other  canners  were  also  early  in  the  asparagus  field  and  the  Cali- 
fornia Fruit  Canners'  Association,  after  its  organization,  began 
to  build  up  an  asparagus  business  which  is  rapidly  enlarging  as  the 
later  planted  fields  come  into  bearing.  Their  cannery  at  Milpitas  (Fig. 
3),  established  originally  by  the  Oakland  Preserving  Company, 
handles  most  of  the  product  of  that  district,  which  is  an  old 
asparagus-growing  section,  while  that  at  Sacramento  (Fig.  4)  was  one 
of  the  first  to  pack  asparagus  and  takes  almost  all  of  the  vegetable 
produced  by  the  growers  on  the  outskirts  of  that  city.  They  have 
further  an  asparagus  cannery  at  Vorden,  on  the  great  Van  Loben  Sels 
estate  (Fig.  5),  and  likewise  pack  more  or  less  asparagus  in  their 
San  Francisco  canneries. 

The  Golden  State  Asparagus  Company  is  the  third  of  the  important 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  11 

asparagus  packers.  Their  new  cannery  at  Andrus  Island  (Fig.  6) 
is  well  equipped  for  the  business  and  situated  in  the  midst  of  their 
large  and  increasing  asparagus  fields.  The  Goetjen  and  Metsen  fields 
on  Grand  Island  are  also  under  the  control  of  this  company. 


Fig.  6.    Andrus  Island  cannery.    Golden  State  Asparagus  Company. 

Hunt  Brothers,  large  fruit  and  vegetable   canners,  have  recently 
built  a  small  asparagus  cannery,  at  Antioch  (Fig.  7)  to  pack  aspara- 


Fig.  7.    Hunt  Bros.'  asparagus  cannery.    Antioch. 

gus  from  various  points  in  the  island  section  which  they  have  con- 
tracted. An  asparagus  cannery  has  also  been  built  at  the  Sylvester 
&  Graves  place  below  Stockton. 

Other  companies  can  more  or  less  asparagus  from  the  city  markets, 


12  UNIVERSITY    OF    CALIFORNIA— EXPERIMENT   STATION. 

but  these  comprise  all  those  who  make  a  specialty  of  the  business, 
packing  directly  from  the  fields.  The  process  is  clean  and  appetizing 
and  the  product  healthful  and  delicious,  being  immeasurably  superior 
to  fresh  asparagus  bought  in  the  market  and  cooked  at  home. 

Asparagus  is  grown  in  gardens  all  over  the  State  and  commercially, 
in  a  small  way,  near  most  of  the  larger  cities.  In  Orange  County  a 
number  of  growers  are  engaged  in  producing  fresh  asparagus  for  the 
early  Chicago  market.  The  warmer  portions  of  the  State  do  not  seem 
as  favorable  to  the  crop,  and  the  fine  large  white  asparagus  of  the 
canning  sections  is  not  seen  in  the  south.  Asparagus  has  recently 
been  planted  in  the  Coachella  Desert  country  in  the  Salton  Basin,  and 
hopes  are  entertained  of  the  development  of  a  considerable  industry 
in  that  region. 

There  are  now  about  7,000  acres  of  asparagus  in  California,  includ- 
ing the  flooded  islands,  located  mostly  in  the  river,  Milpitas,  and 
Sacramento  sections.  Of  this,  about  1,500  acres  consists  of  young 
beds  which  will  be  cut  for  the  first  time  in  1905.  No  extensive  new 
planting  has  been  done  since  1902,  but  for  1905  the  planting  of  from 
500  to  1,000  acres  is  contemplated.  The  lower  figure  is  probably 
nearest  the  amount  which  will  be  actually  put  out. 


THE  ASPARAGUS  PLANT. 

Asparagus  (Asparagus  officinalis)  is  a  plant  of  the  lily  family,  a 
native  of  the  old  world,  which  has  been  cultivated  as  a  vegetable  from 
the  earliest  times  for  its  tender  shoots  produced  in  spring.  It  was 
grown  in  Massachusetts  as  early  as  the  seventeenth  century,  and  has 
ever  been  a  popular  vegetable  all  over  the  country.  The  plant  con- 
sists of  a  fleshy,  branching  crown,  rootstock,  or  rhizome,  numerous 
long,  tough  roots,  and  a  number  of  shoots  or  stalks  above  ground 
(Fig.  8).  The  plant  is  perennial,  sending  up  shoots  year  after  year 
almost  indefinitely  if  not  killed  or  injured  in  any  way,  and  is 
difficult  to  eradicate  from  the  soil.  The  roots  are  long,  extending  for 
many  feet  in  depth  and  forming  a  solid  mass  in  old  beds.  The  crowns 
grow  and  branch  extensively  in  all  directions,  with  the  new  growth 
mostly  on  top  of  the  old,  so  that  the  roots  tend  to  come  to  the  surface. 
At  the  ends  and  on  the  sides  of  the  crowns  are  produced  the  buds  from 
which  come  the  shoots  that  grow  up  into  the  air.  When  these  shoots 
are  cut,  new  buds  keep  coming  out  and  the  plants  show  remarkable 
vitality  in  sending  up  stalk  after  stalk  through  the  long  asparagus- 
cutting  season,  when  no  growth  above  ground  is  permitted.  This  can 
not  continue  indefinitely,  however,  but  tops  must  be  allowed  to  grow 
up  in  time  to  mature  and  store  up  new  energy  in  the  plant  for  next 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA. 


13 


year.  Too  long  a  cutting  season  weakens  the  plant  and  hastens  the 
time  when  it  ceases  to  produce  profitably.  Weakness  shows  first  in 
the  size  of  the  stalks,  for  they  become  smaller  when  lacking  vitality. 
When  allowed  to  grow  the  stalks  elongate  very  rapidly,  putting  out 
side  branches  and  small  needle-like  leaves  and  forming  a  thick,  bushy 
top  with  a  height  of  from  three  to  seven  feet  (Fig.  12,  page  17). 
Small  greenish-yellow  blossoms  appear  on  the  branches  at  about  the 
fourth  week  of  the  growth,  from  which  berries  develop,  which,  when 


Fig.  8.    Asparagus  root  and  shoots. 

ripe,  are  bright  red  in  color,  juicy,  and  contain  the  black  seeds.  The 
plants  are  dioecious;  that  is,  male  and  female,  the  latter  alone  bear- 
ing seed. 


CULTURE  OF  ASPARAGUS. 

Asparagus  is  grown  from  seed,  planted  quite  thick  in  close  rows 
in  a  nursery  bed,  and  the  roots  then  transplanted  to  the  permanent 
field.  The  seed  is  thoroughly  soaked  and  warmed  before  planting,  to 
insure  quick  germination.  The  roots  may  be  transplanted  when  one, 
two,  or  three  years  old,  but  in  California  are  most  satisfactory  at  one 
year,  if  well  grown.  They  are  dug  in  the  winter  after  the  tops  die 
down,  allowed  to  dry  if  kept  long,  and  planted  as  early  as  possible  in 


14  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT    STATION. 

the  spring.  The  permanent  bed  must  be  in  a  soil  specially  suited  to 
asparagus  if  it  is  to  succeed,  particularly  for  canning-asparagus, 
which  requires  a  large  production  of  high  quality  for  profit.  The 
typical  California  asparagus  soils  are  of  two  classes:  the  sediment 
soils,  as  at  Sacramento  and  Milpitas,  composed  of  fine,  sedimentary 
river  deposits,  and  the  island  peat  soils,  composed  in  places,  on  the 
San  Joaquin  side  particularly,  of  almost  pure  organic  matter;  or 
again,  on  the  Sacramento,  of  mixtures  of  peat  and  sediment  or  clay 
in  various  proportions.  The  structure  of  the  island  soil  formations 
varies  considerably,  some  having  pure  peat  to  a  depth  of  thirty  feet 
or  more,  as  at  Bouldin  Island,  others  with  underlying  strata  of  clay 
and  sediment  at  various  depths.  The  soil  must  be  fertile,  naturally 
moist  or  capable  of  irrigation,  well  drained,  and  not  forming  hard 
lumps.  The  last  is  especially  essential  in  growing  straight  stalks  for 
canning. 

The  distance  between  the  rows  varies  in  different  sections.  At 
Sacramento,  where  new  soil  and  manure  are  applied,  every  year,  they 
are  five  feet  apart.  This  is  very  close,  except  for  small  fields  on  valu- 
able land.  At  Milpitas  seven  feet  is  the  usual  distance,  while  in  the 
great  island  plantations  nine  or  even  ten  feet  is  a  common  distance. 
In  this  soft  soil  the  crowns  spread  very  rapidly  and  close  planting 
makes  a  short-lived  bed,  the  asparagus  soon  becoming  crowded  and 
running  down  in  size.  The  distance  between  plants  varies  in  the  same 
way.  Nine  feet  by  two  is  advisable  in  the  island  section,  and  about 
seven  by  one  and  a  half  on  sediment  soil.  Where  quick  returns  are 
more  desired  than  long  life,  as  on  leased  lands,  closer  planting  is 
advisable,  up  to  four  feet  by  one.  This  will  give  a  large  yield  for  a 
few  years,  but  will  soon  run  out. 

The  roots  are  planted  in  a  deep  furrow  which  is  gradually  filled  as  the 
plants  grow.  In  countries  where  manuring  is  customary  a  trench  is 
made  and  filled  at  the  bottom  with  manure,  over  which  the  roots  are 
planted.  The  plants  should  be  allowed  to  grow  two  years  before  any 
cutting  is  done.  In  the  third  year  cutting  should  stop  early  in  the 
season,  not  continuing  over  six  weeks.  During  these  first  two  years 
it  is  customary  to  grow  some  annual  crop  between  the  rows.  This  is 
useful  in  keeping  the  ground  cultivated  so  long  as  the  asparagus  plants 
do  not  suffer.  Careless  tenants  sometimes  injure  the  latter  more  than 
the  value  of  the  temporary  crop.  Clean  cultivation  and  no  breaking 
down  of  the  asparagus  must  be  insisted  on.  Crops  thus  commonly 
grown  are  beans,  potatoes,  and  onions,  of  which  the  first  is  least 
objectionable. 

Asparagus  may  be  grown  either  green  or  white,  according  as  the 
shoots  are  allowed  to  grow  several  inches  above  ground  before  being  cut. 
or  are  cut  as  soon  as  the  top  breaks  the  surface.     In  the  latter  method 


ASPARAGUS   AND   ASPARAGUS   RUST    IN    CALIFORNIA. 


15 


by  which  all  the  canning  asparagus  is  grown,  the  dirt  is  ridged  up  high 
on  the  rows  in  order  to  produce  long,  tender,  white  stalks  (Fig.  9). 
These  ridges  are  put  up  in  early  spring  as  soon  as  the  ground  can  be 
worked,  and  kept  up  through  the  cutting  season  (Fig.  10).  They  are 
made  by  plows,  disks,  hand  implements,  and  various  special  machines 
devised  by  different  growers.  Much  the  best  of  these  is  the  modified 
disk  cultivator  devised  by  Mr.  Boots,  and  in  use  by  him  and  others. 

The  asparagus  shoots  are  cut,  as  soon  as  the  top  appears,  by  means 
of  a  long-handled  gouge  (Fig.  11),  carried  out  of  the  field  in  baskets. 


1 

i  f 

j 

1                   iJmk   ■ 

CI                                               %  1  H 

Fig. 


Section  of  asparagus  row 


washed,  trimmed  to  a  uniform  length  of  seven  inches,  packed  in  bulk 
into  60-pound  boxes  (see  cover),  a  burlap  and  slat  cover  tacked  on, 
and  the  boxes  then  sent  to  the  cannery  or  market.  In  the  East 
asparagus  is  sold  in  bunches— 1*4  pounds  in  Boston,  with  a  wholesale 
unit  of  a  three-dozen-bunch  box,  while  New  York  takes  a  2V2~pound 
bunch,  sold  at  wholesale  by  the  dozen.  Boston  requires  green  aspara- 
gus; New  York  and  most  other  markets,  white.  Bunching  is  not 
practiced  to  any  extent  in  California,  except  for  the  earliest  asparagus, 
which  is  shipped  East  in  the  fresh  condition. 


16 


UNIVERSITY   OF    CALIFORNIA— EXPERIMENT   STATION. 


Cutting  begins  somewhat  in  February,  but  is  quite  light  until  late 
in  March,  when  the  canneries  open.     The  season  varies  in  length,  with 


Fig.  10.    Asparagus  field  in  cutting  season. 


a  tendency  for  the  canneries  to  run  longer  each  year  on  account  of 
the  demand  for  canned  asparagus.     They  close  during  the  latter  part 


Fig.  11.    Chinamen  cutting  asparagus. 


of  June  and  early  in  July,  making  a  season  of  from  ninety  to  one 
hundred  days. 

The  yield  of  asparagus  in  California  is  large,  compared  with  East- 


ASPARAGUS   AND   ASPARAGUS    RUST   IN    CALIFORNIA. 


17 


ern  districts.     This  is  on  account  of  the  long  cutting  and  growing 
season  and  the  deep,  fertile  soil;  5,000  pounds  of  merchantable  aspar- 


Fig.  12.    Asparagus  plant,  showing  continual  development  of  new  shoots. 

agus  per  acre  is  no  more  than  a  fair  average  for  large  plantations,  esti- 
mating producing  fields  of  all  ages  together,  while  in  good  fields  of 
prime   age   7,000   or  8,000   pounds   are   often  produced  without   any 


Fig.  13.    Field  of  asparagus  in  fall. 

fertilization.     By  reason  of  these  large  yields  and  the  excellent  quality 
of  the  product,  no  other  portion  of  the   country  can   compete  with 
California  in  canning  asparagus. 
2— bul.  165 


18  UNIVERSITY    OF    CALIFORNIA— EXPERIMENT   STATION. 

After  the  cutting  season  the  rows  are  plowed,  disked,  or  harrowed 
down  as  flat  as  possible,  and  the  shoots  at  once  grow  up  and  produce 
the  thick  tops  (Figs.  12  and  13).  These  remain  until  late  in  November 
or  December,  when  they  become  mature  and  are  killed  by  frost.  Then 
the  old  tops  are  cut,  the  stubble  chopped  out  with  hoes,  the  fields 
plowed,  harrowed,  and  prepared  for  the  new  crop.  The  beds  should 
be  cultivated  and  kept  clean  all  through  the  summer,  though  too  often 
this  is  neglected  after  the  tops  grow  up. 

In  the  majority  of  cases  asparagus  is  grown  in  California  on  a 
share  system  with  Chinese  tenants,  the  owner  furnishing  land,  uten- 
sils, horses,  and  all  necessities  for  handling  the  crop,  while  the  China- 
man supplies  the  labor  and  receives  fifty  or  sixty  per  cent  of  the 
product. 


THE  ASPARAGUS  RUST. 

Asparagus  rust  is  a  disease  of  the  asparagus  plant.  In  Europe  it 
has  been  known  for  at  least  a  century,  and  is  as  old,  no  doubt,  as  the 
history  of  the  plant  itself  as  a  cultivated  vegetable.  No  great  impor- 
tance, however,  attaches  itself  ordinarily  to  the  rust  in  the  old  world, 
as  it  is  neither  abundant  nor  destructive,  although  the  writer  has 
recently  learned  of  a  considerable  outbreak  in  the  Brunswick  region 
during  the  past  year  or  two.  Further  information  in  regard  to  this 
case  would  be  of  much  interest,  and  perhaps  shed  more  light  on  the 
remarkably  sudden  and  destructive  occurrence  of  the  disease  in  this 
country.  As  known  at  present  the  rust  started  in  epidemic  form  in 
the  North  Atlantic  States  during  the  fall  of  1896.  Dr.  B.  D.  Halsted1 
of  the  New  Jersey  Experiment  Station  was  the  first  to  call  public 
attention  to  the  matter  at  that  time,  and  states  "after  a  full  corre- 
spondence with  botanists,  horticulturists,  and  asparagus-growers,  that 
the  outbreak  of  the  rust  seemed  to  be  limited  in  that  year  (1896)  to  New 
England,  Long  Island,  New  Jersey  and  Delaware."  In  1897  the  rust 
was  much  worse  in  the  regions  previously  affected  and  extended  to  the 
South  Carolina  fields  about  Charleston,  spreading  to  the  south  and 
west.  In  the  asparagus  centers  of  Massachusetts,  Rhode  Island,  Long 
Island,  New  Jersey,  Delaware,  Maryland,  and  the  other  asparagus- 
growing  regions  in  the  Atlantic  States,  the  green  tops  were  completely 
killed  in  July,  creating  a  condition  which  certainly  had  not  occurred 
before.  In  the  meantime,  Professor  HaLsted2  states  from  his  corre- 
spondence with  persons  in  every  State  and  Territory,  that  "the  vast 

iBulletin  129,  N.   J.  Agr.  Expt.   Sta.,  1898. 

2Annual    Reports    of    N.    J.    Agr.    Expt.    Sta.,    1897-190H. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  19 

interior  and  the  western  part  of  the  United  States  seem  as  yet  free 
from  rust"  (1897).  In  1898  the  disease  was  less  abundant  in  some 
of  the  first  affected  sections,  but  was  found  for  the  first  time  as  far  west 
as  Michigan.  Rust  was  again  very  prevalent  in  the  East  in  1899,  and 
was  found  in  Illinois,  Ohio,  and  Kansas.  In  1900  the  Atlantic  States 
were  again  badly  affected,  while  its  regular  westward  progress  brought 
the  rust  into  the  Dakotas,  Nebraska,  and  Texas,  or,  in  other  words,  out 
to  the  semi-arid  States  and  Territories  east  of  California,  which  have 
no  asparagus  fields  of  any  extent. 

In  spreaddng  from  Massachusetts  to  Texas  during  these  five  years 
the  rust  usually  made  its  first  appearance  in  each  State  in  the  largest 
asparagus  sections,  as  would  be  expected.  From  these  places  smaller 
beds  soon  became  affected,  so  that,  on  the  whole,  the  progress  of  the 
disease  was  remarkably  uniform  from  east  to  west  across  the  country. 
In  1902  and  1903  the  rust  was  much  less  abundant  in  the  Eastern 
States,  for  reasons  which  will  be  discussed  hereafter,  while  in  1904, 
although  somewhat  more  prevalent,  the  attack  occurred  later  in  the 
season  and  little  damage  is  to  be  apprehended.  After  the  first  few 
years  of  the  epidemic  most  of  the  older  beds  in  the  Atlantic  States  were 
entirely  destroyed,  the  canning  industry  was  practically  abandoned, 
prices  became  about  double  what  they  had  previously  been,  new  varie- 
ties came  into  use,  and  an  entire  readjustment  of  the  asparagus  indus- 
try took  place. 

It  is  idle  to  speculate  on  the  origin  of  this  epidemic  and  remarkable 
spread  of  asparagus  rust  in  the  United  States  as  just  described.  That 
the  rust  existed  in  eastern  Massachusetts  and  Long  Island  previous  to 
1896  many  growers  in  those  sections  feel  convinced.  That  it  never 
occurred  before  in  any  such  destructive  manner  is  morally  certain. 
Farther  west,  in  the  Central  States,  there  are  not  lacking  those  who 
claim  to  have  seen  asparagus  rust  long  before  the  present  outbreak,  and 
some  whose  observations  are  worthy  of  consideration.  The  situation 
in  California,  as  will  be  shown,  is  similar,  and  on  the  whole  the  writer 
is  not  prepared  to  deny  that  asparagus  rust  had  existed  in  this 
country  to  a  limited  and  unimportant  extent  previous  to  1896.  That 
an  entirely  new  and  distinct  outbreak,  of  unparalleled  severity,  started 
in  that  year  and  spread  across  the  country  can  not  be  doubted.  The 
idea  entertained  by  some  that  the  rust,  previously  overlooked,  simply 
came  to  be  noticed  at  this  time  on  account  of  the  unusual  attention 
attracted  by  it,  can  not  be  seriously  considered.  Such  damage  as  has 
been  caused  in  recent  years  could  not  fail  to  have  attracted  attention 
had  it  occurred  previously,  and  the  condition  of  the  plants  would  have 
been  noticed  previous  to  the  years  mentioned  above  by  those  who  were 
looking  especially  for  rust  in  the  various  States. 


20  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION. 

THE  RUST  IN  CALIFORNIA. 

The  same  uncertainty  attends  the  history  of  asparagus  rust  in  Cali- 
fornia as  in  other  sections  of  the  country.  While  a  distinct  epidemic 
has  occurred  during  the  past  three  or  four  years,  the  progress  of 
which  can  be  easily  traced,  we  can  by  no  means  be  certain  that  this  is 
the  beginning  of  the  matter.  Of  particular  interest  is  the  fact  that 
in  the  year  1880,  the  late  Dr.  Harkness  published,  in  a  list  of  fungi 
of  the  Pacific  Coast,  the  name  Puccinia  asparagi,  the  asparagus  rust, 
from  Sacramento.  This  is  the  only  published  mention  of  the  rust  in  the 
United  States  previous  to  1896.  No  specimen  was  preserved  and  a  mis- 
take may  have  been  made,  though  the  fungus  is  easily  identified.  To 
the  best  and  most  observant  growers  in  the  State  the  disease  was 
entirely  new  at  its  recent  appearance,  and  we  may  feel  sure  that 
previous  to  1901  there  was  no  rust  in  the  large  asparagus-growing 
sections  of  the  State  in  any  such  form  as  has  occurred  since  that  time. 
It  is  still  the  writer's  conclusion,  based  upon  various  facts  and  observa- 
tions by  himself  and  others,  that  asparagus  rust  may  have  occurred 
in  California,  to  a  very  limited  and  unimportant  extent,  for  a  number 
of  years.  There  is  indeed  some  evidence  to  show  that  a  slight  epidemic 
occurred  in  one  section  of  the  State  some  forty  years  ago,  though  this 
again  is  uncertain. 

The  present  outbreak  appears  to  have  started  in  southern  California 
as  early  at  least  as  1900  or  1901,  some  placing  the  date  even  earlier. 
The  growers  first  noticed  it  in  1901.  No  report  of  the  matter  was  made 
until  1902,  when  the  rust  was  also  present  on  all  the  fields  in  the 
Milpitas  district,  near  San  Jose.  From  the  growers '  observations 
there  was  rust  in  the  latter  section  on  some  of  the  beds  in  1901,  and 
probably  that  year  for  the  first  time.  Thus  it  is  seen  that  the  epidemic 
in  California  connects  in  time  with  that  coming  from  the  East,  which 
reached  Texas  in  1900. 

In  1902  the  California  State  Board  of  Horticulture  passed 
a  resolution  prohibiting  the  importation  of  asparagus  roots  or  seedr 
into  the  State,  but  as  the  rust  was  already  present  this  regulation  was 
of  no  avail. 

At  Bouldin  Island  Mr.  E.  A.  Schultz,  a  most  careful  observer,  kept 
close  watch  for  rust,  and  first  detected  it  in  October,  1902.  Examin- 
ing the  surrounding  region  he  found  the  disease  present  in  a  scat- 
tering manner  as  far  north  as  Grand  Island. 

Since  the  taking-up  of  the  work  by  the  writer  in  the  spring  of  1903, 
the  matter  has  been  closely  followed  and  definite  statements  can  be 
made.  In  the  fall  of  that  year  the  rust  outbreak  occurred  for  the 
first  time  at  Vorden  and  Sacramento,  thus  including  the  most  northern 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  21 

of  the  large  asparagus  sections.  Small  beds  at  Marysville,  Chico,  and 
other  northern  points  were  not  affected  in  1903  or  1904.  Santa 
Barbara,  Fresno,  and  other  intermediate  points  in  the  State  were 
found  infested  in  1903,  and  no  doubt  the  rust  was  there  before  then. 
The  spread  of  the  disease  is  thus  seen  to  have  been  from  south  to  north 
in  the  State;  southern  California  1901  or  sooner,  Milpitas  1901, 
Bouldin  Island  and  surrounding  section  up  to  Grand  Island  1902, 
Vorden  and  Sacramento  1903.  As  in  other  States  the  spread  has  not 
been  entirely  regular,  reaching  forward  into  the  larger  asparagus 
sections  at  first,  then  extending  to  the  smaller  beds,  but  these  dates 
represent  accurately  the  main  advance  of  the  rust  epidemic  in 
California. 

With  all  the  uncertainties  and  doubtful  features  connected  with  the 
origin  and  spread  of  the  disease,  these  facts  are  positive  and  indispu- 
table. The  asparagus  plantations  of  the  United  States  were  healthy 
and  free  from  any  pronounced  symptoms  of  rust  up  to  1896.  The 
disastrous  outbreak  of  disease  started  in  August  of  that  year  from  the 
Atlantic  Coast,  and  finally  reached  Sacramento,  California,  in  August, 
1903,  affecting  every  important  asparagus-growing  section  in  the 
country  in  the  general  order  outlined  above.  Whether  or  not  the  rust 
existed  here  before,  and  wherever  it  may  have  been,  this  was  certainly 
a  new  and  distinct  occurrence,  having  no  connection  with  previous 
conditions  and  presenting  a  remarkable  example  of  the  spread  of  a 
plant  disease,  affecting  a  not  over-common  crop,  over  the  entire  coun- 
try wherever  the  crop  is  grown  at  all  extensively,  within  a  period  of 
seven  years. 

NATURE  OF  THE  RUST. 

Rust  is  a  disease  which  does  not  affect  directly  the  asparagus  which 
is  cut  for  market,  but  makes  its  appearance  only  upon  the  green  tops 
which  grow  up  after  cutting  has  ceased.  By  killing  these  tops,  which 
should  grow  and  store  up  strength  in  the  roots  for  the  next  year's 
crop,  the  disease  weakens  the  plant,  diminishes  the  yield  and  quality 
of  the  product,  and  if  severe  enough  kills  the  plant  entirely.  The 
trouble  is  ordinarily  first  noticed  by  the  careful  observer,  by  the  pres- 
ence of  red  spots  in  the  thick  mass  of  green  tops.  This  may  occur 
at  any  time  after  the  tops  branch,  blossom,  and  "feather"  out, 
depending,  in  California,  upon  weather  conditions  and  the  nearness  of 
rust  infection.  In  the  worst  affected  places  rust  appears  as  soon  as 
the  tops  are  grown,  while  in  the  open  island  country  it  may  not  come 
on  until  October.  The  red  spots  may  be  as  large  as  one's  hand  when 
first  noticed.  If  examined  more  closely  it  will  be  seen  that  the  red 
color  is  due  to  a  condition  shown  in  Fig.  19  on  page  29,  the  stems  and 
needles  being  covered  with  little  blisters  from  which  a  reddish  "rusty" 


22 


UNIVERSITY   OF    CALIFORNIA— EXPERIMENT   STATION. 


powder  escapes.  If  one  is  familiar  with  the  disease  and  searches  care- 
fully, he  may  detect  it  even  before  the  red  spots  are  large  enough  to  be 
evident.  He  will  find  at  the  very  first  single  blisters  here  and  there, 
producing  the  red  powder,  as  in  Fig.  14.  About  these  the  larger 
rusty  areas  develop,  and,  spreading  rapidly  if  conditions  are  favorable, 
the  isolated  spot  soon  extends  up  and  down  the  row,  across  to  adjoining 
rows,  connects  with  other  similar  spots,  and  with  great  rapidity  the 
whole  field  is  soon  red  and  rusty.  On  passing  through  the  tops  one's 
hands  and  clothing  become  colored  by  the  dark  red  powder  from  the 
innumerable  rust  blisters  on  every  twig  and  needle,  and  a  cloud  of 


Fig.  14.    First  appearance  of  Uredo  (red)  Rust  on  twigs  and  needles  (X,  X). 

the  same  dust  scatters  into  the  air.  Soon  the  red  tops  begin  to  turn 
to  a  bright  yellow,  giving  an  appearance  of  premature  maturity.  The 
needles  fall  to  the  ground,  the  yellow  color  is  lost,  and  now  nothing 
remains  but  the  bare,  dead  stalks,  still  covered  by  rust  pustules,  which 
become  black  in  color  and  no  longer  dusty  (Fig.  23,  page  35).  This  is 
the  final  stage,  and  the  sight  of  his  fields  dead  and  black  in  August  or 
September,  when  formerly  they  presented  a  mass  of  rich  green  foliage 
dotted  with  the  coral-red  berries,  is  a  most  distressing  one  to  the 
asparagus-grower. 

Still  another  form  of  rust  may  be  seen  in  the  early  part  of  the 
season  during  the  cutting  season,  upon  asparagus  which  is  allowed  to 
grow  up  at  that  time.     This  likewise  appears  as  a  breaking  out  on 


ASPARAGUS    AND   ASPARAGUS   RUST    IN    CALIFORNIA.  23 

the  surface  of  the  plant,  but  more  upon  the  main  stem  and  branches 
than  upon  the  needles.  There  first  appear  oval-shaped  patches  of  a 
lighter  green  than  the  normal.  From  these  little  round  pustules  develop 
in  concentric  lines,  each  pustule  opening  into  a  little  cup  from  which 
scatters  a  powder  dust.  This  form  occurs  only  early  in  the  season 
and  disappears  in  June  or  July,  giving  place  to  the  single  red  and 
black  pustules  described  above.  All  three  forms  may  often  be  seen 
together  on  stalks  which  grew  up  in  the  spring,  the  red  and  black 
forms  breaking  out  around  the  edges  of  the  light  green  ovals.  These 
three  forms  are  called  respectively  the  spring,  summer  or  red,  and  fall 
or  black  rust,  and  are  to  be  seen  in  abundance  at  the  proper  season 
in  any  of  our  asparagus-growing  districts.  They  all  represent  one  and 
the  same  disease  in  its  different  variations.  The  rust  is  easy  to  deter- 
mine and  no  one  can  mistake  its  symptoms  when  once  familiar  with 
them. 

CAUSE  OF  THE  RUST. 

The  cause  of  the  rust  is  well  known,  having  been  described 
by  the  French  botanist  de  Candolle  as  early  as  1805,  a  century  ago. 
The  disease  is  produced  by  a  parasitic  fungus  named  by  de  Candiolle 
Puccinia  asparagi.  This  fungus  is  one  of  the  true  rusts,  a  very  char- 
acteristic type  of  parasites,  with  such  other  examples  as  the  grain  rust, 
rusts  of  various  grasses,  carnation,  rust,  prune  and  peach  rust,  and 
many  others  of  common  occurrence.  These  rusts  are  vegetable  in 
their  nature,  plants  in  fact,  but  strict  parasites,  being  able  to  exist 
only  upon  the  particular  plants  which  they  affect. 

The  visible  part  of  the  asparagus  rust-fungus  is  represented  by  the 
blisters,  pustules,  etc.,  which  break  out  on  the  surface  of  the  plant, 
and  the  dusty  powder  which  comes  from  these  eruptions.  That  this  is 
a  definite  fungus,  a  true  parasitic  plant,  can  easily  be  seen  with  the 
microscope.  That  it  is  the  cause  of  the  trouble  with  the  asparagus 
may  be  considered  self-evident,  but  can  easily  be  demonstrated  by 
shaking  a  rusty  stalk  in  the  dusty  condition  over  unaffected  tops  when 
wet  with  dew ;  or  the  experiment  may  be  performed  more  carefully  by 
placing  a  small  quantity  of  the  red  dust  in  a  known  spot  on  a  healthy 
plant,  where  it  will  be  moist  and  shaded  for  a  few  hours  or  over 
night.     From  such  infections  the  disease  will  soon  appear. 

This  red  dust  which  gives  the  rusty  appearance,  the  black  pustules 
of  the  fall  rust,  and  the  dusty  powder  which  comes  from  the  little 
cups  in  the  spring  rust,  all  represent  the  spores  of  the  fungus,  and, 
although  the  dust  is  very  fine,  each  particle  is  a  single  spore  capa- 
ble of  starting  the  rust  anew.  Beneath  each  pustule  of  rust  on  the 
surface  the  plant  tissue  is  permeated  by  a  mass  of  fine  filament  thread's 


24 


UNIVERSITY   OF   CALIFORNIA— EXPERIMENT    STATION. 


which  absorb  nourishment  for  the  parasite  and  thereby  injure  the 
plant.  '  Each  needle  becomes  full  of  the  fungous  growth,  the  surface 
tissues  of  the  stem  are  likewise  affected,  and  all  the  green  parts  of  the 
plant  become  thoroughly  infested  with  the  vegetative  portion  or 
mycelium  of  the  fungus.  The  spores  are  then  produced  and  pushed 
out  through  the  surface.  These,  then,  are  the  two  parts  of  the  fungus ; 
the  mycelium  or  inside  growth,  invisible  to  the  sight,  and  the  spores, 
three  different  forms,  which  break  out  on  the  surface. 


THE   MYCELIUM. 


The     filaments     of     the     rust     fungus     have     no     peculiar     struc- 
ture,   but    are    long,    narrow,    and    extensively    branched,    ramifying 


Fig.  15.    Cross-section  of  asparagus  needle. 

between  the  cells  of  the  green  parts  of  the  plant,  but  extending  only 
very  slightly  into  the  more  solid  portions.  Fig.  15  represents  the 
structure  of  an  asparagus  needle  or  small  branch,  in  cross-section.  On 
the  outside  appears  the  epidermis,  a  single  layer  of  thick-walled  cells. 
Next,  a  three-cell  layer  of  delicate  tissue.  These  cells  contain  the  green 
chlorophyll  and  give  the  plant  its  color.  In  the  center  is  a  fibrous  por- 
tion. In  the  larger  stems  the  fibrous  part  becomes  increased,  while  the 
green  is  still  a  thin  surface  tissue.  Fig.  16  represents  one  of  the 
green  cells  much  more  enlarged.  In  it  are  seen  the  numerous  large 
chlorophyll  granules  which  have  the  green  color. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA. 


25 


Fig.  16  also  shows  more  of  these  cells  with  their  contents  affected 
by  the  rust-fungus  filaments,  which  are  represented  between  them. 
These  filaments  run  all  through  the  green  tissue  in  this  way.  They 
pass  between  rather  than  into  the  cells,  forcing  them  apart,  but  at 
numerous  points  the  haustoria  (a,  a,  a,  of  the  figure)  develop,  which 
appress  themselves  closely  to  the  sides  of  the  cells,  making  an  indenta- 
tion and  perhaps  breaking  through  into  the  interior  in  some  cases. 
These  are  the  absorptive  organs  which  take  up  nourishment  for  the 
fungus  out  of  the  plant  cells  and  disastrously  affect  the  latter.  The 
mycelium,  starting  first  as  shown  in  Fig.  22  on  page  31  and  explained 
later,  spreads  through  the  green  cell  tissue  in  all  directions  in  the  man- 


Fig.  16.    Effect  of  rust  mycelium  on  plant  cells. 

ner  shown  in  the  figures,  and  finally,  gathering  into  a  thick  mass  at  cer- 
tain points  just  under  the  epidermis,  produces  and  pushes  out  through 
the  surface  a  spore  pustule,  as  in  Figs.  20  and  24  on  pages  30  and  36. 
In  each  of  these  illustrations  is  seen  the  aggregation  of  mycelium  just 
under  the  spore  cluster.  In  the  figure  of  the  spring  rust  (Fig.  18, 
page  28)  will  be  seen  how  all  the  cells  are  crowded  apart  by  the  fungous 
growth  between  them,  and  this  produces  the  light-colored  oval  spot  in 
\vhich  the  spore  cups  develop. 


Effect  of  the  Rust  Mycelium  on  the  Cells  and  Tissues. — The  green 
cell  tissue  of  plants  is,  in  a  physiological  sense,  most  important,  having 
functions  much  beyond  that  of  simply  giving  color  to  the  leaves  and 
other  green  parts.     Structurally,  as  we  have  seen,  the  green  matter  is 


26  UNIVERSITY   OF    CALIFORNIA  —  EXPERIMENT    STATION. 

in  the  form  of  corpuscles,  contained  in  large,  thin-sided  cells  just 
under  the  epidermis.  In  the  asparagus  leaves  or  needles  it  extends 
practically  to  the  center,  but  on  the  stem  and  branches  forms  a  thin 
surface  layer,  which  may  be  readily  seen  and  scraped  away  after 
peeling  off  the  delicate,  colorless  epidermis  on  the  surface.  It  is  the 
function  of  this  green  tissue  to  carry  on  a  process  by  which  plant-food 
is  formed  out  of  the  raw  materials  provided  by  nature.  The  plant 
takes  in  water  from  the  soil  and  carbonic  acid  gas  from  the  air.  These 
substances  are  decomposed  by  the  action  of  the  green  corpuscles  during 
sunlight  and  reunited  into  starch,  sugar,  and  similar  carbohydrates. 
This  is  the  fundamental  process  in  plant  nutrition  and  precedes  all 
other  digestive  operations.  The  importance  of  the  chloroplasts 
(chlorophyll  grains)  is,  therefore,  apparent. 

Fig.  16  is  intended  to  represent  in  detail  the  effect  of  the  rust 
mycelium  upon  the  green  tissue  which  it  inhabits.  In  a  general  way  it 
may  be  said  that  the  filaments  absorb  food  for  the  fungus  out  of  that 
assimilated  by  the  plant,  and  thus  weaken  the  latter  to  that  extent, 
but  the  effect  is  much  more  than  this.  Comparing  the  figures  in  order 
from  left  to  right,  the  pronounced  effect  upon  the  chloroplasts  will  be 
observed.  In  the  normal  cell  they  are  plump,  rounded,  and  distributed 
uniformly  about  the  circumference  of  the  cell,  free  from  one  another. 
A  rust  filament  coming  into  contact  with  the  cell  does  not  merely 
absorb  nutritive  substances  from  it.  The  chloroplasts  immediately 
begin  to  shrivel,  collapse,  draw  together  in  the  interior  of  the  cell,  and 
indicate  by  their  appearance  that  they  are  dead  and  functionless.  The 
mass  runs  together,  then  by  continued  shrinking  divides  usually  into 
three  portions,  as  shown.  The  cell  is  now  dead,  and  as  the  whole  leaf, 
the  whole  plant,  and  the  whole  field  become  similarly  affected,  the 
change  from  green,  to  red,  yellow,  and  finally  brown,  or  the  color  of 
dead  tops,  gradually  takes  place.  The  sudden  death  of  the  tops  and 
weakening  of  the  plant  in  vitality  are  explained  by  the  active  destruc- 
tion of  its  green  tissue  and  most  vital  part,  rather  than  by  the  loss  of 
the  amount  of  nutriment  which  the  parasite  takes  to  itself. 

The  exact  effect  of  the  mycelium  upon  the  chloroplasts,  and  its  cause,  present 
one  of  the  interesting  and  important  problems  of  plant  pathology.  Here  is  the 
critical  point  in  the  phenomena  of  parasitism.  A  filament,  coming  into  contact  with 
an  uninjured  cell,  sends  out  haustoria,  which  penetrate  the  cell  only  slightly,  if 
at  all,  and  immediately  the  chloroplasts  begin  to  react  as  briefly  described  above. 
Apparently  a  soluble  substance,  poisonous  or  enzymatic,  is  excreted,  to  bring  about 
this  effect.  The  question  calls  to  mind  further  the  various  degrees  and  rapidity 
of  disintegration  and  destruction  produced  in  this  way  by  other  rusts,  some  living 
almost  as  in  symbiosis  with  their  hosts,  or  at  least  producing  little  damage  for  a 
long  period,  somo  causing  irritation,  structural  changes,  and  abnormalities,  but  not 
premature  death,  some  gradually  killing  the  plant  or  affected  part,  but  very  few  so 
rapidly  and  generally  destructive  as  the  asparagus  rust. 

Going  back  to  infection  by  the  spore  (Figs.  21  and  22  on  page  31),  it  is  again  of 
interest  to  recall   the  phenomena  of  monoxeny,  or  limitation  of  certain  parasites  to 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  27 

single  host  species,  polyoxeny,  the  heterrecious  rusts,  and  similar  features  of  para- 
sitism. Structural  peculiarities,  both  in  host  and  parasite,  must  be  considered  as 
exerting  important  influences,  but  the  reaction  between  germ-tube  or  mycelium  of 
the  parasite  on  the  one  hand,  and  the  cell  contents  of  the  host  on  the  other,  be  it 
chemical,  physical,  or  vital,  is  parasitism,  and  the  power  to  influence  the  delicate 
adjustment  upon  which  this  reaction  hinges  would  carry  with  it  infinite  possibilities 
in  the  treatment  of  pathological  problems. 

SPORE  FORMS  OF  PUCCINIA  ASPARAGI. 

Having  described  the  mycelium  of  the  fungus  which  flourishes  in 
the  tissues  of  the  affected  plant,  we  may  now  consider  the  various 
spore  forms  already  alluded  to : 

Spring  Rust,  or  JEcidiwm  Stage. 

The  spring  rust  form  of  the  parasite  may  be  observed  abundantly 
in  California  at  almost  any  place  where  rust  occurred  the  year  before 
and  asparagus  plants  are  allowed  to  grow  up  without  being  cut.  It  is 
most  commonly  seen  on  volunteer  plants,  young  beds  not  cut,  and  old 
abandoned  fields.  In  such  places  it  usually  appears  upon  the  first 
stalks  which  come  up,  but  is  most  abundant  in  April  and  May.  Spring 
rust  is  not  rare  in  March  and  has  been  found  by  the  writer  even  in 
February  on  early  stalks.  Later  than  June  it  does  not  develop  much 
in  this  climate,  but  passes  into  the  other  stages.  The  oval,  lighter- 
green  patches  on  the  stems  and  branches  which  characterize  this  form 
of  rust,  are  shown  in  Fig.  17.  The  single  larger  pustules  are  the 
red  rust,  but  the  oval  areas  of  small  pustules  represent  the  aecidia,  or 
spring  rust.  The  light-colored  ovals  are  simply  places  where  the  inner 
tissue  is  full  of  mycelium,  ready  to  produce  spores.  Climatic  or 
other  influences  bring  about  the  development  of  the  different  kinds  of 
spores  at  different  seasons.  The  small  pustules  on  the  aecidial  patches 
push  up  from  the  inside  and  finally  break  open  into  little  cups,  easily 
visible  with  an  ordinary  magnifier.  In  these  cups  are  the  spores, 
small,  round  particles  of  living  matter,  each  capable  of  sprouting  and 
reproducing  the  fungus  under  favorable  conditions.  These  aecidial 
spores  are  produced  in  chains,  coming  up  from  the  mass  of  mycelium 
at  the  base  of  the  cup  and  breaking  up  into  single  spores  at  the  outside. 
Fig.  18  represents  a  section  through  an  aecidial  spot,  the  cup  at  the 
left  beginning  to  push  up  the  epidermis,  but  not  yet  open,  while  the 
other  has  opened  and  is  scattering  its  spores.  The  plant  cells  are 
pushed  apart  by  the  mass  of  filaments  which  fill  in  solidly  between 
them. 

Red  Rust,  or  Uredo  Stage. 

The  rust  which  appears  on  asparagus  fields  in  summer  after  the 
tops  grow  up  is  quite  different  in  appearance  from  the  spring  form. 
This  uredo  stage  begins  to  show  itself  quite  early,  along  with  the  spring 


28 


UNIVERSITY    OF    CALIFORNIA  — EXPERIMENT    STATION. 


m 


Fig.  17.    Spring  Rust  (JEcidia)  on  asparagus  stalks.    Stalk  at    right 
shows  first  infection  at  surface  of  the  ground. 


Fk,.  1*.    Cross-section  of  jEcidial  stage  or  Spring  Rust. 


ASPARAGUS    AND    ASPARAGUS    RUST    IN    CALIFORNIA. 


29 


rust,  as  in  Fig.  17.  It  breaks  out  in  single  pustules,  pushing  out 
through  the  epidermis  and  discharging  the  red  rusty  spore  dust  very 
profusely.  In  fields  badly  affected  in  July  or  August  every  branch  and 
needle  is  covered  with  the  rust  pustules  of  this  stage,  as  in  Fig.  19. 
Fig.  20  shows  a  section  of  part  of  such  a  pustule,  representing  the 
mycelium  amongst  the  cells  and  spores  breaking  out  through  the  epi- 
dermis very  much  enlarged.  The  spores  are  produced  singly,  and  are 
seen  in  various  stages  of  development  at  the  ends  of  the  filaments. 
These  spores  have  the  dark  red  color  which  gives  the  disease  its  name, 
and  a  structure  quite  similar  to  that  of  the  ascidial  spores. 


Fig.  19.    Uredo  (red)  Rust. 

Germination  of  Spores  and  Summer  Infection.  —  The  spread  of  the 
rust  by  secidio-  and  uredospores  is  similar  and  need  not  be  separately 
described.  Carried  by  the  wind  or  in  any  other  way  to  the  surface 
of  an  asparagus  plant,  the  spore,  if  conditions  are  favorable,  imme- 
diately sprouts,  sending  out  a  tubular  filament,  as  in  Figs.  21  and  22. 
This  grows  along  on  the  epidermis,  but  soon  turns  downward  into  the 
plant,  commonly  through  a  breathing  pore,  as  in  Fig.  21,  but  possi- 
bly boring  directly  through  in  some  cases.  The  writer  has  never 
observed  the  latter  case.  Passing  down  through  the  opening,  as  seen 
in  cross-section  in  Fig.  22,  the  sprout  enters  the  space  beneath,  extends 
down  between  the  cells,  begins  to  affect  them  as  previously  described, 
and   soon   spreads   in  all   directions   in   the   green  tissue.      This   new 


30 


UNIVERSITY    OF    CALIFORNIA— EXPERIMENT    STATION. 


mycelium  aggregates  again  into  spore  pustules,  and  thus  another  gen- 
eration of  rust  is  formed. 

Distribution.— Asparagus   rust   may   theoretically   be    spread    in    a 
variety  of  ways,  by  any  object  or  agency  which  passes  from  infested 


Fig.  20.    Cross-section  of  rust  (Uredo)  blister. 

regions  to  those  not  yet  affected.  When  one  sees  the  cloud  of  dust 
which  arises  from  rusty  plants  when  disturbed,  coloring  men's  hands 
and  clothing,  horses'  legs,  cultivators,  wagon  poles  and  wheels,  and 
anything  passing  through  the  field  a  deep  red  color,  flying  away  in 
the  wind  like  smoke,  covering  the  berries  which  contain  the  seed, 
covering  and  coloring  the  ground  from  which  roots  are  dug  for  sale, 
and  reflects  that  each  minute  particle  of  this  dust  is  a  rust  spore,  it 


ASPARAGUS   AND   ASPARAGUS   RUST    IN    CALIFORNIA, 


31 


Fig.  21.    Uredospore  germinating  on  surface  of  plant,  and  separate  spores. 


Fig.  22.    Cross-section,  showing  infection  from  rust  spore. 


32  UNIVERSITY    OF    CALIFORNIA— EXPERIMENT    STATION. 

would  seem  that  the  spread  of  the  disease  must  occur  in  many  different 
ways  through  the  agency  of  these  summer  spores.  Practically,  how- 
ever, there  appears  to  be  but  one  mode  of  distribution  at  all  common, 
which  is  the  distribution  of  uredospores  by  the  wind.  Locally  no 
doubt  other  agencies  come  in.  Birds,  animals,  and  workmen,  passing 
about  the  fields,  very  likely  hasten  the  progress  of  the  parasite  some- 
what, although  without  such  aid  but  little  difference  would  be  seen  in 
the  rate  of  progress  of  the  disease.  That  the  rust  is  carried  long 
distances,  as  from  State  to  State  or  from  the  East  to  California,  by 
means  of  seeds,  roots,  or  traffic  of  any  sort  is  extremely  doubtful. 
The  progress  of  the  disease  has  been  too  regular  to  be  accounted  for  in 
this  way.  Asparagus  seed  and  roots  were  imported  from  the  East  to 
various  parts  of  California  during  the  entire  rust  epidemic  there,  yet 
the  disease  came  up  gradually  from  south  to  north  at  the  conclusion  of 
its  seven-year  steady  journey  from  the  Atlantic,  with  no  indication 
of  starting  here  and  there  in  the  State,  as  would  be  the  case  if  brought 
in  on  roots  and  seed,  and  also  not  appearing  any  sooner  at  the  places 
where  Eastern  importations  were  planted  than  at  all  the  other  places 
in  the  same  region.  All  the  indications  go  to  show  that  the  rust  has 
been  a  most  independent  traveler,  requiring  no  aid  from  man  to  carry 
it  on  its  way. 

In  its  local  distribution  by  wind  the  rust  shows  certain  peculiarities 
in  California.  Chief  of  these  is  the  marked  tendency  of  the  disease  to 
travel  agai?ist  the  prevailing  wind,  from  east  to  west.  This  is  very 
decided  in  districts  where  the  rust  is  abundant.  The  writer  can  only 
account  for  this  by  supposing  that  the  prevailing  summer  west  winds 
are  too  strong  and  dry  to  promote  uniform  drifting  along  of  the 
infection  from  plant  to  plant.  He  has  often  noticed,  in  the  aspara- 
gus districts  where  the  condition  under  discussion  is  most  prominent, 
that  at  about  sunrise  on  certain  mornings  a  slow  creeping  current  of 
mist,  close  to  the  ground,  drifts  in  from  east  to  west,  being  dissipated 
soon  after  sunrise  by  the  usual  wind  springing  up  from  the  opposite 
direction.  It  seems  probable  that  infection  is  spread  locally,  at  least, 
by  such  slow  moisture  currents  in  the  air  rather  than  by  the  strong, 
dry  prevailing  winds.  In  fact,  the  whole  spread  of  the  rust  over  the 
country  has  shown  no  particular  relationship  to  the  latter  currents  of 
air,  in  spite  of  the  fact  that  distribution  has  so  evidently  been  through 
the  atmosphere. 

Introduction  of  rust  by  means  of  the  dusty  spring  or  summer  spores 
clinging  to  seeds  or  roots  is  especially  unlikely,  although  they  are  so 
abundant  and  cover  everything  in  the  asparagus  field,  for  two  reasons: 
The  short  life  of  these  spores,  and  the  fact  that  they  germinate  and 
perish  at  once  when  in  contact  with  moisture,  whether  on  asparagus  or 
not.     This  brings  up  another  subject: 


ASPARAGUS   AND   ASPARAGUS   RUST    IN    CALIFORNIA. 


33 


Condition^  Affecting  Germination  and  Infection. — Two  conditions 
are  necessary  to  sprout  the  aecidio-  and  uredospores;  namely,  a 
proper  degree  of  warmth  and  moisture.  The  former  is  a  minor 
consideration,  as  the  ordinary  temperature  at  any  time  when  asparagus 
is  growing  is  sufficient  to  germinate  rust  spores.  The  moisture  relation 
is  of  great  practical  importance,  particularly  in  California.  The 
summer  rust  spores,  like  most  seeds  and  other  vegetable  reproductive 
bodies,  require  moisture  for  germination.  When  thus  supplied  they 
sprout  at  once,  and  if  the  spore  has  been  previously  deposited  upon 
an  asparagus  plant,  and  no  unfavorable  conditions  exist,  infection 
takes  place  as  has  been  described.  Thus  it  is  readily  seen  how  the  mist 
current  drifting  along  through  the  asparagus  tops,  or  an  ordinary 
dew,  will  serve  to  start  infection  from  any  rust  spores  which  may  be 
present.  But  wherever  the  dusty  spores  may  be  they  sprout  as  soon 
as  they  get  wet,  so  that  if  not  on  asparagus  the  delicate  germ-tube  dries 
up  and  perishes  as  soon  as  the  sun  gets  high,  which  is  the  end  of  that 
spore.  Countless  numbers  of  spores  on  the  ground,  on  other  plants 
than  asparagus,  and  wherever  they  happen  to  fall,  perish  in  this  way. 
It  is  for  this  reason  that  distribution  of  rust  by  the  dusty  summer 
spores  clinging  to  seeds  and  roots  is  not  possible,  since  with  the 
planting  of  the  same  the  spores  would  become  moistened,  sprout  in 
the  ground,  if  at  all,  and  perish  long  before  the  asparagus  came  up 
to  be  infected.  The  whole  process  of  germination  and  infection 
requires  only  a  few  hours. 

If  kept  dry  the  period  during  which  the  aecidio-  and  uredospores 
retain  their  germinative  power  is  comparatively  short,  as  shown  in 
Table  I. 

TABLE  I. 
Showing  Period  of  Vitality  of  ^Ecidio-  and  Uredospores  When   Kept  Dry. 


Source. 


Gathered. 

Tested. 

June    8 

June  20 

June    8 

July     2 

June    8 

July     9 

June    8 

July  18 

June  18 

June  20 

June  18 

July     2 

June  18 

July     9 

June  18 

July  18 

June  18 

June  20 

June  18 

July     2 

June  18 

July     9 

June  18 

July  18 

June  18 

Sept.  28 

June    8 

Sept.  28 
July     2 

June  26 

June  26 

July  18 

June  26 

Dec.    12 

Germination. 


JEcidiospores 

Bouldin  Island 

Bouldin  Island. 

Bouldin  Island _.. 

Bouldin  Island 

Milpitas 

Milpitas 

Milpitas _ 

Milpitas 

Uredospores. 

Milpitas __ _ 

Milpitas 

Milpitas 

Milpitas _.. 

Milpitas 

Bouldin  Island 

Riverside . ._ 

Riverside 

Riverside 


Good 

Very  feeble 

...Little  or  none 

-_ None 

—Good 

A  few 

Apparently  none 
None 

Good 

.Good 

Good 

-.- Good 

None 

None 

—  Good 

Good 

None 


3— BUL.  165 


34  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT    STATION. 

It  is  seen  here  that  the  spring  spores  will  sprout  no  longer  after 
being  kept  dry  for  a  month,  while  the  uredospores,  though  somewhat 
longer  lived,  retain  their  vitality  for  only  three  or  four  months  at 
most.  This  again  precludes  wide  distribution  by  such  spores  on  seeds 
and  roots. 

The  amount  of  moisture  required  to  sprout  the  spores  is  not  great. 
If  placed  on  a  dry  surface,  in  a  closed  moist  chamber  or  glass  dish 
where  the  air  is  saturated  with  moisture,  germination  soon  starts.  In 
a  drop  of  water  the  spores  sprout  immediately,  as  in  Fig.  21.  The 
lightest  dew  is  therefore  sufficient  to  start  germination.  In  the  field 
it  is  necessary  that  the  moisture  should  remain  for  at  least  a  few 
hours  in  order  to  give  the  sprouting  filaments  time  to  get  down  into 
the  inside  tissues  before  the  sun  dries  them  up.  For  this  reason  a  light 
dew  deposited  just  before  sunrise  and  quickly  drying  again  does  not 
start  infection;  and  for  the  same  reason  rust  is  seen  first  in  the  shel- 
tered spots  among  the  tops  and  wherever  the  dew  lies  longest.  Rain  is 
less  favorable  to  rust  infection  than  dew,  except  as  it  subsequently 
increases  the  amount  of  the  latter  form  of  moisture.  A  heavy  rain 
seems  to  wash  the  spores  from  the  plant  and  often  improves  its 
appearance. 

The  fact  that  rust  spores  depend  absolutely  upon  atmospheric 
moisture;  to  germinate  and  infect  asparagus  has  been  shown  by  the 
writer  in  his  previous  publications1 2  and  need  not  again  be 
elaborated  here.  The  plainest  demonstration  of  this  is  the  green 
healthy  growth  of  asparagus  seen  beneath  any  thick  tree  which  happens 
to  stand  in  a  field,  when  all  the  rest  of  the  tops  are  black  and  dead. 
The  fact,  previously  announced  by  the  writer,1  that  ' '  dew  is  of  absolute 
necessity  in  infection  by  the  rust"  and  that  "without  moisture  of  this 
sort  no  infection  can  take  place,  regardless  of  all  other  conditions," 
has  been  most  successfully  taken  advantage  of  in  California,  as  pre- 
viously shown  in  Circular  No.  9,  and  referred  to  again  later  in  this 
work. 

Infection  naturally  follows  germination  of  the  spores  when  they 
sprout  on  asparagus  plants.  We  may2  therefore,  notice  here  the  logical 
and  rational  nature  of  the  preventive  measures  of  summer  infection 
outlined  in  another  chapter.  First  of  all,  natural  parasites  may  come 
in  to  destroy  the  rust  spores.  Beyond  this  the  first  operation  consists 
in  keeping  the  rust  as  far  away  as  possible  from  the  fields  by  allowing 
no  rusty  asparagus  to  grow  near  by.  This  keeps  the  spores  out  of  the 
field  for  a  longer  or  shorter  period,  when  no  infection  can  take  place. 
After  this  resource  is  exhausted  and  rust  spores  begin  to  blow  in  from 
unavoidable  sources,  imagine  an  individual  case  as  in  Fig.  22.     A  spore 

iCircular   No.    9,    Calif.    Expt.    Station,    1903. 
2Botanical  Gazette,  vol.  38,  p.  19,  1904. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA. 


35 


falls  on  an  asparagus  branch  or  needle.  Dew  is  deposited  and  it 
sprouts.  This  can  not  be  prevented.  The  sprout  lengthens  and  starts 
to  penetrate  the  plant.  Here  is  the  next  possibility  of,  prevention, 
by  ventilating  the  field  as  much  as  possible,  so  that  the  moisture,  if 
not  too  much,  may  be  dried  up  by  the  wind  before  the  sprout  gets  into 
the  plant,  or  even  kept  down  enough  to  prevent  germination  altogether. 

"When  this  fails  and  sufficient  moisture  for  infection  can  not  be 
prevented,  spraying  and  similar  operations 
come  in,  by  which,  so  far  as  they  are  suc- 
cessful, the  spray  substance  kills  the  delicate 
germ-tube  before  it  gets  far  enough  to  infect 
the  plant.  Finally,  if  the  sprout,  escaping 
all  the  plans  laid  for  its  destruction,  reaches 
the  interior  tissues  uninjured,  the  only  hope 
remaining  is  in  the  plant  itself.  Resistant 
varieties  or  plants  of  great  vitality  may,  by 
their  peculiar  qualities,  resist  the  action  of 
the  fungus  in  their  tissues  and  not  respond  to 
its  effects. 

This  covers  the  whole  field  of  summer-rust 
prevention. 

Black  Rust,  or  Teleato  Stage. 

This  has  been  briefly  described  in  its  gen- 
eral features.  Often  called  the  fall  rust,  its 
appearance  is  by  no  means  limited  to  that 
season.,  but  is  then  most  abundant  and  char- 
acteristic. As  the  writer  has  shown,1  this 
form  is  that  assumed  by  the  rust  under  any 
conditions  unfavorable  to  it,  whether  because 
the  air  is  very  dry,  the  plant  weak  and  exhausted  and  furnishing  little 
nutriment,  or,  as  most  common,  when  winter  approaches  and  the  rust 
must  live  over  in  some  form  until  spring.  The  insufficiency  of  the 
other  two  forms  of  spores  for  such  a  function  has  been  shown.  They 
could  not  live  through  the  winter,  but  would  sprout  on  the  ground  as 
soon  as  moistened.  In  dry  weather  they  would  soon  lose  their  vitality. 
They  are  easily  affected  by  parasites,  and  in  every  way  more  adapted 
for  spreading  the  rust  rapidly  when  conditions  are  favorable,  while 
with  the  teleutospores  the  contrary  is  true. 

The  appearance  of  the  black  rust  is  quite  different  from  that  of  the 
other  stages,  both  to  the  eye  and  under  the  microscope.  The  spore 
pustules  are  black  and  free  upon  the  surface,  rather  than  under  a 


Fig.  23.    Black  (Teleuto)  Rust. 


lBotanical  Gazette,  loc.  cit. 


36 


UNIVERSITY    OF    CALIFORNIA— EXPERIMENT   STATION. 


FIG.  24.    Section  through  black  rust  pustule,  showing  Teleutospores. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  37 

blister  of  the  epidermis  (Fig.  23).  In  many  cases,  early  in  the  season, 
mixed  pustules  of  red  and  black  spores  occur,  giving  a  brown  color, 
but  in  the  fall  and  winter,  on  the  dead  asparagus  branches,  the  rust 
is  black  and  very  prominent. 

Fig.  24  shows  a  partial  section  of  a  pustule  of  black  rust.  The 
spores,  as  seen,  are  dark-colored,  thick-walled,  two-celled,  and  borne 
singly  on  long  stems  which  come  up  from  the  mycelium.  Structurally 
they  require  no  further  description.  These  spores  are  not  dusty  like 
the  summer  form,  but  stick  firmly  to  the  plant  in  the  original  clusters 
where  they  grew.  When  disturbed  they  give  off  no  dust  (the  old  tops 
sometimes  become  moldy  with  other  fungi)  and  show  no  adaptation 
whatever  for  rapid  spread  through  the  air.  The  peculiar  office  of  these 
spores,  which  are  produced  so  abundantly  in  the  fall,  is  to  carry  the 
fungus  over  winter.  After  the  red  rust  has  done  its  work  and  the 
asparagus  tops  are  yellow  and  exhausted,  the  masses  of  black  spores 
develop  on  the  same  needles  and  branches  and  from  the  same  mycelium 
as  the  red  form  which  preceded  them.  With  the  fall  rains,  storms, 
and  death  of  the  tops,  the  needles  and  finer  branches  fall  to  the 
ground,  leaving  the  bare  stalks  standing.  All  are  covered  with  black 
rust.  It  is  customary  and  everywhere  recommended  to  cut  and  burn 
the  old  tops  at  this  time,  to  get  them  out  of  the  way  and  destroy  as 
much  rust  as  possible.  But  if  the  surface  of  the  ground  be  closely 
examined  it  will  be  seen  that  there  is  rust  enough  left  in  the  field 
even  after  raking  and  burning  the  old  tops  as  thoroughly  as  can  be 
practically  done.  Fig.  25  represents  a  bird's-eye  view  of  the  surface 
of  the  ground  in  a  rusty  asparagus  field  in  December,  after  the  tops 
had  been  cut  and  burned.  The  rusty  twigs  and  needles  are  seen  in 
great  abundance,  while  the  surface  soil  is  full  of  older  withered  needles 
with  the  rust  spores  upon  them.  Fig.  26  shows  such  old  dead  needles 
from  the  soil  and  the  pustules  of  black  rust  upon  them.  Examined 
with  the  microscope,  the  masses  of  spores  are  found  still  intact,  just 
as  they  grew,  although  little  is  left  of  the  asparagus  needle. 

Teleutospore  Germination  and  Infection.— If  the  black  spores  in 
summer  or  fall  be  placed  in  water  and  under  conditions  in  every  way 
favorable,  they  show  no  indication  of  germination  or  sprouting.  This 
is  to  be  expected,  since  otherwise  they  would  all  sprout  and  perish  in 
the  fall,  when  no  asparagus  was  growing  to  carry  on  the  fungus. 
Table  II  shows  the  results  of  germination  tests  with  teleutospores. 


38 


UNIVERSITY   OF    CALIFORNIA— EXPERIMENT    STATION. 


TABLE    II. 


Source. 


Gathered. 


Bouldin  Island 
Bouldin  Island 
Bouldin  Island 
Bouldin  Island 
Bouldin  Island 
Bouldin  Island 

Milpitas 

Bouldin  Island 
Grand  Island.. 

Vorden 

Milpitas 

Bouldin  Island 

Milpitas .. 

Milpitas 

Milpitas 

Milpitas 

Milpitas 

Milpitas 

Milpitas 

Milpitas 

Milpitas 

Milpitas 

Milpitas.. 


June  8, '03 
June  8, '03 
June  8, '03 
June  8. '03 
June  8, '03 
July  15,  '03 
Sept.  22,  '03 
Oct.  1,  '03 
Oct.  1,  '03 
1,'03 
12,  '03 
20,  '03 


Oct 
Oct 
Oct 


Nov.  19,  '03 
Dec.     1,  '03 


Dec.  23,  '03 

Jan.  6,  '04 

Jan.  9,  '04 

Jan.  9,  '04 

Jan.  23, '04 

Jan.  23, '04 

Feb.  14, '04 

Feb.  18. '04 
June  27,  '04 


Tested. 


June  20,  '03 
July  2, '03 
July  9,*03 
July  18,  '03 
Sept.  28,  '03 
July  18, '03 
Sept.  28, '03 
Oct  6,  '03 
6. '03 
6, '03 
28,  '03 
28,  X)3 
12,  '03 
12,  '03 


Oct. 
Oct. 
Oct. 
Oct. 
Dec. 
Dec. 


Dec.  25, '03 
Jan.    6, '04 

Jan.     9,  '04 


Jan. 
Jan. 
Jan. 
Feb. 
Feb. 


14,  '04 
24,  '04 
24,  '04 
14,  '04 
26.  '04 


June  27,  '04 


Germination. 


None 

..None 

__. .None 

_ ..None 

None 

None 

None 

. None 

-. None 

None 

..None 

None 

-.    None 

A  few  spores 

sprout 

..More  than  last 
None 

.  Very  few  germ. 

Many  germ. 

..Some 

..None 

Many 

Abundant 

One  spore  germ, 
in  many  tests. 


Remarks. 


First  frosts  and  consider- 
able rain  latter  part  of 
November. 

Tested  at  outdoor  tem- 
perature. 

Heavy  frosts  and  freezing 
temperature,  Jan.  7-10. 

Kept  at  90-100°  F. 
At  about  60°  F. 


Used  spores  from  old  last 
year's  stalks  in  aban- 
doned field. 


From  these  tests  the  nature  of  the  conditions  which  promote  germi- 
nation is  quite  evident.  Like  some  seeds,  the  teleutospores  require 
a  period  of  rest  and  particularly  the  influence  of  frost  and  winter 
storms  upon  them  to  make  them  sprout.  It  is  seen  that  with  the  first 
frost  the  spores  began  to  show  signs  of  germinative  capacity,  which 
increased  more  and  more  as  the  winter  progressed.  Variation  in  the 
results  of  the  tests  from  week  to  week  are  no  doubt  due  largely  to 
variations  in  the  temperature  and  moisture  at  which  the  test  was  made. 
In  most  cases  the  old  rusty  stalks  were  gathered  from  the  field  on 
the  dates  given,  soaked  up  in  warm  water,  and  then  placed  over  night 
or  longer  in  a  moist  chamber  at  living-room  temperature.  The  tests 
on  January  6  and  January  23  at  lower  temperatures  indicate  that  a 
fair  degree  of  warmth  is  necessary  to  start  germination,  so  that  spores 
would  not  sprout  out  of  doors  until  the  first  warm  days  of  spring. 
The  extreme  weather  of  January  7-10  seemed  to  retard  germination 
for  a  short  time,  but  after  a  few  days  the  spores  sprouted  more  vig- 
orously than  ever. 

In  brief,  we  may  conclude  that  the  conditions  which  start  the  aspar- 
agus into  growth  in  the  spring  are  identical  with  those  which  promote 
germination  of  the  teleutospores,  so  that  the  parasite  is  ready  to 
attack  its  host  whenever  it  starts  into  growth.     The  first  rust  of  1904 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA. 


39 


was  observed  by  the  writer  on  February  9,  after  some  warm  days  which 
started  a  few  asparagus  stalks  into  growth.  This  was  in  an  abandoned 
field  where  the  rusty  last  year's  stalks  were  not  cut  or  the  ground  dis- 


Fig.  25.    Bird's-eye  view  of  surface  of  the  ground  in  rusty  asparagus  field  in  fall, 
showing  rusty  twigs  and  needles. 

turbed,  so  that  the  new  growth  coming  up  in  the  midst  of  the  old  was 
exposed  to  infection  to  an  unusual  extent. 

The  test  of  June  27  with  last  fall's  black  rust  shows  that  by  that 
time  vitality  was  practically 
extioct  in  the  old  spores,  or  that 
all  had  germinated  previously. 
This  accords  with  experience,  as 
there  is  no  infection  in  the  fields 
as  late  as  this,  except  from  the 
new  rust  of  the  season  on  early 
asparagus  tops. 

The  germinative  process  in  the 
teleutospores  is  peculiar,  and 
quite  different  from  that  of  the 
other  forms.  Fig.  27  represents 
the  germination  of  three  spores. 
Each  cell  sends  out  a  germ-tube 


Fig.  26.    Old  rusty  needles  from  the  soil  in  fall. 


at  the  points  represented,  which  grows  up  for  a  short  distance,  thick, 
short  and  club-shaped,  then  divides  at  the  end  into  four  divisions. 
Each  of  these  cells  puts  out  a  side  branch,  and  on  the  end  of  this  a 


40 


UNIVERSITY   OF    CALIFORNIA— EXPERIMENT    STATION. 


small  secondary  spore  is  produced,  called  a  sporidium.  The  original 
teleutospores,  as  already  explained,  remain  on  the  ground  or  wherever 
the   asparagus   twigs   dropped.     If  the   old   stalks   were   not   cut   the 

spores  are  still  on  them  as 
long  as  they  exist.  There  is 
no  dust  flying-about  of  the 
teleutospores,  and  they  ordi- 
narily never  come  into  con- 
tact with  the  new  growth  of 
asparagus  which  they  infect. 
The  sporidia  are  very  small 
and  light,  easily  move  in  the 
wind,  and  are  the  spores 
which  directly  infect  the  new 
asparagus  in  spring. 

It  must  be  borne  in  mind 
that  in  the  case  of  spring  rust- 
infection,  the  asparagus  in 
the  main  fields  is  being  cut 
as  fast  as  the  stalks  come  up, 
so  that  these  plants  can  not 
get  the  disease  at  this  time. 
The  surface  of  the  ground, 
which  is  full  of  the  old  aspar- 
agus needles  and  twigs  cov- 
ered with  black  rust,  is 
continually  worked  over 
through  the  cutting  season 
from  February  to  July,  so 
that  all  the  spores  become 
exposed  to  moisture  and  no 
doubt  sprout  and  then  per- 
ish without  causing  any 
infection.  Eust  does  not 
originate  in  the  field,  in  Cal- 
ifornia at  least,  after  the 
tops  come  up  in  July,  but 
comes  in  from  the  outside 
earlier       growth.       Infection 

Fic.27.    Germination  of  Teleuiospores  and  production     from  the  old  black  rust   lying 
of  Sporidia.  * 

over  winter  is  limited  entirely 
to  asparagus  which  is  not  cut,  to  young  or  abandoned  beds,  and  to 
volunteer,  wild  asparagus.  Such  plants  grow  up  when  the  teleuto- 
spores are  germinating  in  the  soil  and  on  old  stalks,  and  become  infected 


ASPARAGUS  AND  ASPARAGUS  RUST  IN  CALIFORNIA.  41 

by  the  sporidia.  These  small  spores  send  a  sprout  into  the  plant  tissue 
and  soon  develop  a  new  mycelium.  Now  appears  on  the  surface  the 
spring,  aecidial  rust,  beginning  a  new  generation.  In  fields  of  young 
asparagus  where  last  year's  rusty  tops  were  removed,  the  first  spring 
rust  spots  result  from  infection  by  teleutospores  in  the  soil  and  come 
out  near  the  base  of  the  stem  (Fig.  17,  page  28).  A  crop  of  spring 
spores  from  these  soon  infest  the  stem  higher  up  and  others  near  it. 
In  case  the  old  stalks  are  left  standing  the  new  ones  grow  up  among 
them  and  become  infested  at  any  point. 

Possibility  of  Introducing  Bust  on  Asparagus  Boots  by  Teleuto- 
spores.—This  is  the  only  case  in  which  there  is  any  possibility  of 
introducing  rust  into  a  new  locality  by  importing  roots,  and  even  of 
this  there  is  very  little  chance.  The  surface  soil  in  rusty  seed  beds  is 
full  of  teleutospores  on  old  twigs  and  needles,  so  that  when  the  roots 
are  dug  and  the  soil  turned  over  it  would  not  be  surprising  if  some 
dirt  containing  spores  should  stick  to  them.  These  spores  might  then 
be  carried  wherever  the  roots  went,  germinate  at  the  proper  time,  and 
produce  rust  on  the  new  plants.  In  practice  it  is  doubtful  if  this 
ever  occurs.  With  roots  shipped  to  any  distance  all  dirt  is  washed  or 
shaken  from  the  roots  as  much  as  possible  to  avoid  extra  weight.  When 
the  roots  are  replanted  they  are  buried  deep  below  the  surface,  which 
would  put  any  attached  rust  spores  completely  out  of  the  way;  the 
spores,  if  any  got  a  chance  to  sprout,  would  probably  do  so  before  the 
asparagus  comes  up ;  and  in  every  way  the  chances  of  any  teleuto- 
spores, in  the  improbable  case  of  their  being  on  the  roots,  germina- 
ting just  at  the  right  time  and  place  to  infect  the  asparagus  are  very 
remote.  The  writer  has  seen  repeated  cases  in  this  State  where  part 
of  the  roots  in  a  rusty  seed  bed  were  replanted  in  new  land,  in  one 
case  not  over  a  hundred  feet  from  the  bed,  and  a  few  rows  left  undis- 
turbed in  the  old  bed.  The  latter  showed  abundant  spring  rust  on  the 
earlier  growth,  while  the  plants  that  had  been  moved,  even  but  a 
short  distance,  had  no  sign  of  rust  until  it  came  through  the  air  and 
produced  summer  rust  later  in  the  season.  In  such  a  case,  where  the 
roots  were  dug  and  replanted  at  once,  by  the  same  men,  using  the 
same  implements  with  the  dirt  fresh  upon  them,  the  chances  of  carry- 
ing infection  are  very  much  greater  than  in  shipping  dried  and  cleaned 
roots  long  distances.  Practically,  then,  the  distribution  of  rust  in  this 
manner  is  possible,  but  very  improbable.  Especially  significant 
against  the  idea  of  rust  introduction  by  spores  on  roots  and  seeds  is 
the  fact  already  stated  that  the  disease  has  taken  a  definite  course 
in  the  State  from  south  to  north,  and  has  not  appeared  any  sooner  at 
places  where  Eastern  roots  were  planted. 


42  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT    STATION. 

NATURE  OF  THE  INJURY  CAUSED  BY  RUST 

The  fact  that  asparagus  rust  does  not  affect  directly  the  product 
cut  for  market  need  lead  no  one  to  suppose  that  no  damage  results 
from  the  attacks  of  the  disease.  The  cutting  of  asparagus  shoots  as 
fast  as  they  start  up  for  a  period  of  several  months  is  at  best  a  most 
unnatural  operation.  That  this  can  be  done  and  the  plant  survive 
and  nourish  from  year  to  year  for  a  long  period  is  indicative  of  great 
vigor  of  growth  on  the  part  of  the  crop.  This  vigor  is  located  in  the 
large  root-stocks  or  crowns  of  the  plant,  produced  and  stored  up  for 
the  next  season  by  the  growth  of  the  green  tops,  which  come  up  after 
cutting  stops  and  nourish  and  build  up  the  plant  during  the 
remainder  of  the  season.     New  branches  of  the  crown  develop,  eyes 


V 

■  $    ■  ' 

jpri^     I  |  j  ;. 

i        ■■'■      I        &■  ■,      Z'k? 

Fig.  28.    Longitudinal  section  of  healthy  asparagus  root-stock. 

or  buds  are  produced  on  these  to  form  next  year's  shoots,  and  food 
material  is  stored  up  to  support  the  growth  of  such  shoots.  Herein 
lies  the  danger  from  rust.  The  tops  come  up  after  cutting  stops, 
ready  for  a  long  season  of  strengthening  growth.  If  killed  prema- 
turely their  usefulness  is  destroyed  to  that  extent,  the  crowns  are 
weakened,  the  new  shoots  lack  size  and  vitality,  and  next  year's  crop 
shows  the  effect  in  quality  or  quantity,  or  in  both.  With  each  suc- 
ceeding year  of  rust  attack  the  condition  becomes  worse  until  finally 
the  bed  is  killed  or  ceases  to  produce  profitably. 

Accompanying  the  weakening  of  the  crowns  a  decay  often  sets  in 
which  further  hastens  their  destruction.  This  proceeds  downward 
from  the  base  of  the  rust-killed  stalks  into  the  living  tissues  of  the 
root-stock.     Normally  the  old  stalks  in  fall  die  down  and  are  cut  off 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA. 


43 


Fig.  29.    Root-stock  weakened  and  brought  to  decay  by  rust. 


Fig.  30.    Rust-affected  and  decayed  roots. 


44  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT   STATION. 

from  the  underground  crown  by  a  clean  scar  (Fig.  28)  like  a  falling 
leaf  from  the  twig,  but  many  of  the  rusty  stalks  rot  at  the  base,  the 
decay  spreads  into  the  crown  to  the  live  tissue,  and  many  of  next  year's 
buds  are  cut  off  and  destroyed  (Figs.  29  and  30).  This  rotting  is  not 
caused  by  the  rust  fungus  itself.  There  is  no  actual  rust  in  the  root, 
but  by  ordinary  process  of  decay  and  the  effect  of  other  fungi  the 


Wt'          Itt 

Br 

K      ,  'HBB 

1  MM 

1    '**wV; 

■1h          .-ii 

*    1        *l 

I    '         '   tB  ' 

■ 

W  -             \M'.':'    ~'  H 

l^H 

?'<                        '                                  ■'-.:' 

®  1     '  m 

m  ' .    'i.| 

■           1 

-  R  ^  *             Sp 

' 

S9H  f         *          -*o&jbb1 

a  b 

Fig.  81.    a.  Decay  of  asparagus  shoot,    b.  Effect  of  wireworms. 

weakened  and  diseased  tissue  succumbs  to  this  secondary  rust  effect. 
The  appearance  of  red  spots  and  lines  on  the  asparagus  shoots  cut  in 
spring,  with  sometimes  decayed  spots  in  the  same  (Fig.  31a),  an  effect 
sometimes  mistaken  for  rust,  is  to  be  largely  attributed  to  the  same 
source.  The  decay  producing  these  effects  appears  to  be  started 
quite  largely  by  infection  from  the  unhealthy,  partly  rotten  crowns, 
though  other  unfavorable  conditions  may  produce  or  increase  it. 
These  red  spots  are  simply  places  where  decay  has  started,  and  have 
no  direct  connection  with  the  rust. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA. 
AMOUNT  OF  LOSS. 


45 


The  actual  amount  of  injury  from  rust  varies  with  the 
severity  of  its  attacks,  and  quite  largely  with  the  locality, 
soil,  variety  of  asparagus,  and  other  conditions.  It  may  be  said  in 
general,  with  one  exception,  that  the  injurious  effects  in  California 
are  not  as  rapid  as  in  the  Eastern  asparagus  districts.     In  such  typical 


Fig.  32.    Asparagus  stalks  coming  up  from  healthy  roots  after  cutting  season. 

regions  as  Concord,  Mass.,  Mattituck,  Long  Island,  and  Middletown, 
N.  J.,  the  loss  in  quantity  experienced  after  the  first  severe  attack  of 
rust  amounted  to  from  15  to  35  per  cent  of  the  crop,  while  in  three 
years  of  rust  the  susceptible  and  most  commonly  grown  variety  became 
practically  destroyed  and  the  beds  were  abandoned.  This  variety,  the 
Conover's  Colossal,  which  formerly  was  almost  exclusively  grown  on 
the  Atlantic  coast,  is  now  practically  exterminated  in  that  region.     In 


46 


UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION. 


California  the  loss  has  in  most  instances  been  at  first  more  in  quality 
and  size  than  in  number  of  pounds  per  acre.  In  fact,  there  are  cases 
of  actual  increase  in  the  latter  respect  as  a  direct  result  of  the  rust, 
yet  this  should  deceive  no  one  as  to  the  ultimate  result. 

Fig.  32  shows  asparagus  shoots  coming  up  from  healthy  roots,  after 
the  end  of  the  cutting  season.  They  are  seen  to  be  large  and  vigorous, 
rather  few  in  number?  and  growing  to  a  considerable  height  before 
branching.     Fig.  33  shows  the  same  growth  in  a  field  badly  affected 


Fig.  33.    Growth  from  roots  badly  affected  by  rust. 

by  previous  rust.  The  shoots  are  small2  low  branching,  but  very 
numerous.  Fig.  34  shows  the  winter  condition  of  a  root  such  as  in 
Fig.  32  and  one  such  as  the  growth  in  Fig.  33  might  come  from. 
These  illustrations  explain  themselves.  The  rust-weakened  roots  send 
out  numerous  small  buds  and  shoots,  where  normally  they  are  fewer 
in  number  and  larger  in  size.  Thus  may  be  produced  for  a  year  or 
two  a  fair,  or  even  increased  weight,  of  almost  worthless  asparagusi 
The  fact  that  these  small  shoots  are  produced  so  abundantly  must  be 
attributed  to  the  long  California  growing  season,  giving  the  crowns 
vitality  and  opportunity  for  recuperation  much  beyond  that  existing 
under  Eastern  conditions.     Each  year,  however,  the  condition  becomes 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA. 


47 


finally 


worse,  the   value   of   the  product  lessens,    and   abandonment 
results  if  the  rust  continues  to  kill  the  tops  each  summer. 

The  exception,  noted  above,  of  unusually  severe  injury  in  California, 
is  found  in  the  case  of  asparagus  growing  on  the  pure,  deep,  peat  soils, 
the  relation  of  which  to  rust  will  be  alludfed  to  in  considering  the 


Fig.  34.    Asparagus  roots,  showing  comparative  buds  on  healthy  and  rust- 
affeeted,  as  in  Figs.  33  and  34.    Healthy  above. 

relations  of  soils  in  general  to  the  disease.  On  asparagus  growing  in 
such  a  soil  a  loss  of  50  per  cent  in  one  year  has  been  known  to  occur  in 
this  State2  the  beds  being  ruined. 


YEARLY  LIFE  HISTORY  OF  THE  RUST  FUNGUS. 

The  condition  of  the  rust  fungus  during  the  various  seasons,  and  its- 
cycle  of  development  through  the  year,  now  seem  to  be  well  established 
for  California,  according  to  the  description  which  has  preceded.  This 
phase  of  the  subject  is  of  particular  importance  in  considering  methods 
of  controlling  and  preventing  the  disease,  since  an  exact  knowledge  of 


48  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT   STATION. 

the  condition  of  the  parasite  at  all  times,  and  of  the  relations  which 
attend  its  metamorphoses,  should  form  the  basis  of  any  satisfactory 
plan  of  control,  and  may  often  suggest  simple  cultural  methods  by 
which  valuable  and  inexpensive  results  may  be  obtained.  From  the 
account  of  the  various  stages  and  spore-forms  of  the  fungus  we  may 
summarize  the  main  facts  in  its  development  as  follows:  Starting  in 
the  spring,  the  earliest  asparagus  stalks  to  come  up,  in  regions  where 
rust  occurred  the  year  before,  become  infected  with  the  rust  fungus 
on  the  main  stem  near  the  ground.  This  comes  from  spores  of  the 
black,  teleuto  rust,  which  lay  in  the  ground  over  winter.  On  the 
stems  thus  infected,  the  spring,  aecidial  rust  appears.  The  spores  of 
this  stage  soon  mature  and,  carried  by  the  wind,  spread  to  the  side 
branches  and  upper  part  of  the  plant  and  to  other  asparagus  stalks  in 
the  vicinity.  Thus  the  spring  rust  develops,  in  more  or  less  abundance 
during  the  time  from  February  to  July2  on  wild  asparagus,  on  young 
beds,  and  on  anything  not  cut  for  market.  The  spores  sprout  at  once 
when  moistened  the  first  time,  and  if  no  moisture  occurs  they  lose  their 
vitality  in  two  or  three  weeks. 

In  May  or  earlier  the  affected  asparagus  begins  to  show  the  red, 
uredo  rust,  as  well  as  the  ascidial  form.  This  produces  more  abundant 
and  more  dusty  spores  and  distributes  the  fungus  by  wind  very  rapidly 
under  favorable  conditions.  All  this  time  the  producing  fields  are 
being  cut.  At  the  end  of  the  cutting  season  all  the  rust  is  someivkere 
on  growing  asparagus.  There  is  none  in  the  soil  of  the  main  beds.. 
Cultivation  through  the  long  cutting-season  has  eradicated  that  which 
was  present  in  the  fall.  Observation  of  the  first  appearance  of  rust  in 
the  fields  in  July  or  later,  indicates  in  every  instance  that  it  comes 
from  the  outside,  from  rusty  asparagus  somewhere  else.  The  plainest 
illustration  of  this  is  seen  in  cases  like  Fig.  35,  where  wild  asparagus 
grows  about  the  edge  of  the  field,  or  where  one  rusty  field  infects  an 
adjoining  clean  one;  but  even  in  cases  of  considerably  isolated  planta- 
tions the  rust  at  first  is  seen  to  drop  in  here  and  there  on  the  tops*, 
brought  long  distances  by  the  wind,  and  does  not  start  on  the  lower 
main  stems  as  occurs  in  infection  from  the  soil. 

The  red  rust  spreads  over  the  field,  killing  the  tops,  working  from 
above  down,  and  not,  as  in  the  soil-produced  spring  rust,  from  below 
upwards.  Finally  the  red  changes  to  black,  the  green  growth  to  brown 
.dead-looking  stalks,  and  the  season  is  ended.  All  the  uredospores 
germinate  when  moistened,  and  keep  their  vitality  when  dry  only  a 
few  weeks ;  consequently  they  have  no  apparent  relation  to  the  winter- 
ing of  the  fungus  or  its  survival  from  year  to  year. 

The  black  teleutospores  remain  attached  to  the  dead  needles,  twigs 
and  stems  upon  which  they  were  produced.     The  finer  stuff  falls  to  the 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  49 

ground  and  covers  or  becomes  mixed  with  the  soil.  The  main  stalks 
stand  until  removed  or  destroyed  by  the  elements.  These  spores  do 
not  germinate  at  all  during  the  year  when  they  were  produced,  but  lie 
exposed  to  the  rain  and  frost  through  the  winter.  After  being  acted 
on  by  frost,  and  being  constantly  more  or  less  moist,  they  begin  to 
sprout  with  the  first  warm  weather  of  early  spring,  at  about  the  time 
when  the  first  asparagus  shoots  start  to  come  up.  If  these  happen  to 
be  such  as  are  not  cut,  but  allowed  to  grow  up,  they  become  infected 
from  the  spores  in  the  ground  and  soon  show  the  oval,  spring  rust  spots 
on  the  main  stems.     In  the  fields  which  are  cut  the  spores  in  the  ground 


Fig.  35.    Wild  asparagus  at  edge  of  field  (on  the  left). 

likewise  sprout,  but  finding  no  growing  asparagus  they  perish,  and 
during  the  whole  cutting  season  the  surface  of  the  ground  is  repeatedly 
stirred  and  turned  over,  so  that  all  the  spores  sprout  and  lose  their 
power  of  infection  before  cutting  stops.  Thus  the  yearly  cycle  is 
completed. 

The  most  suggestive  feature  in  the  life  history  of  the  fungus  thus 
established  is  the  condition  during  the  spring  season  of  about  four 
months,  when  the  main  asparagus  fields  are  being  cut  and;  have  no 
growth  above  ground,  while  the  fungus  at  the  same  time  has  left  its 
dormant  winter  condition  and  requires  growing  asparagus  to  continue 
its  existence.  The  all-important  question  from  a  practical  standpoint 
4— bul.  165 


50  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

is :  Does  the  rust  absolutely  depend  on  growing  asparagus  at  this  time 
for  its  existence,  or  can  it,  in  any  other  possible  way,  pass  from  the 
end  of  one  season  over  to  July  of  the  next  when  the  beds  grow  up, 
without  living  on  asparagus  tops  in  the  meantime?  That  the  former 
case  is  true  in  California  can  scarcely  be  doubted.  In  the  worst 
affected  regions  where  the  tops  have  been  dead  and  covered  with  black 
rust  early  in  the  fall,  and  the  ground  covered  with  rusty  twigs  and 
needles,  as  in  Fig.  25,  page  39,  the  progress  of  the  disease  next  year  can 
be  traced  precisely  from  wild  growth  or  young  beds  into  fields  which 
grew  up  early,  from  the  side  and  even  from  the  plant  nearest  the  wild 
growth,  out  across  the  field,  from  such  fields  to  adjoining  ones  and 
those  which  were  cut  later,  and  so  on  over  the  whole  district.  In  such 
regions  asparagus  grows  wild  everywhere,  old,  abandoned  fields  which 
are  not  cut  are  often  present,  and  the  conclusion  is  almost  absolute 
that  on  the  cutting  fields  rust  comes  always  from  wild  or  earlier  grow- 
ing asparagus,  not  from  the  soil  or  plants  of  the  field  itself,  though  the 
latter  was  covered  with  rust  spores  the  previous  fall.  In  some  of  the 
larger  and  newer  districts  no  wild  asparagus  exists  and  the  fields  are 
located  several  miles  from  any  other  asparagus.  In  these  cases  the 
rust  appears  late  in  the  season  and  comes  on  in  a  scattering  manner, 
apparently  brought  by  the  wind  from  a  considerable  distance  after  the 
disease  becomes  abundant  in  other  places.  "With  so  much  rust  in 
various  scattered  localities  in  all  directions,  it  is  not  remarkable  that 
spores  should  be  brought  into  some  part  of  these  extensive  fields, 
whence  the  disease  soon  spreads  all  over  them.  Furthermore,  the  large 
growers  have  young  fields,  not  cut,  all  of  which  show  more  or  less 
spring  rust  and  help  to  spread  the  disease  into  the  older  fields  when 
they  grow  up. 

It  should  be  said  that  in  other  portions  of  the  country  the  aecidial 
spring  rust  is  by  no  means  as  abundant  as  in  California.  In  the  colder 
portions  where  the  winter  is  long,  it  occurs  rarely,  if  at  all.  In  the 
vicinity  of  Long  Island  and  New  Jersey  it  is  fairly  abundant,  but 
appears  in  June  rather  than  in  February  and  March  as  in  California. 
It  is  still  a  question  how  the  fungus  passes  from  year  to  year  in  the 
colder  regions.  The  occurrence  of  1897-98  in  Massachusetts,  for 
instance,  when  the  rust  was  abundant  during  the  former  year,  but 
appeared  only  in  September  in  1898,  and  in  the  black  teleuto  stage, 
suggests  the  question  how  the  fungus  existed  from  October,  1897,  the 
end  of  that  season,  to  September,  1898,  when  in  almost  every  instance 
it  first  showed  itself  for  that  year.  One  affected  field  is  known  to  have 
existed  earlier  in  the  season,  so  that  possibly  enough  rust  was  present 
in  a  scattering  way  to  start  the  general  infection  later  in  the  season 
when  conditions  became  more  favorable.  Still  more  remarkable  is  the 
case  of  the  bed  mentioned  by  Stone  and  Smith,  well  known  to  and 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  51 

repeatedly  examined  by  the  writer,  where  each  year  a  few  plants  at 
one  end  of  the  bed  showed  a  very  little  black  rust  in  September  and 
October.  There  certainly  was  no  rust  in  this  bed  earlier  in  the  season, 
and  while  it  may  have  blown  in  from  outside  this  does  not  explain 
the  same  plants  being  affected  each  year.  Their  condition  was 
otherwise  in  no  way  different  from  that  of  the  rest  of  the  bed.  The 
case  of  the  asparagus  rust  in  such  regions  of  little  or  no  spring  rust  is 
somewhat  like  that  of  the  chrysanthemum  rust,  which  develops  only  the 
short-lived  uredospores,  yet  exists  from  year  to  year.  Structural 
studies  give  no  evidence  of  a  perennial  mycelium  in  either  case. 

RELATION  OF  NATURAL  CONDITIONS  TO  THE  RUST. 

CLIMATIC   INFLUENCES. 

The  writer  has  already  published  in  Circular  No.  9  of  this  Station, 
and  more  particularly  in  a  technical  paper1,  the  results  of  observa- 
tions on  the  influence  of  climatic  conditions  on  the  development  of  the 
rust  fungus.  It  is,  therefore,  unnecessary  to  repeat  here  the  details  of 
such  observations  and  conclusions.  It  has  been  demonstrated  beyond 
doubt  that  atmospheric  dryness  retards  the  rust,  both  by  preventing 
the  germination  of  the  spores,  and  even  by  retarding  the  development 
of  the  fungus  after  infection  has  taken  place.  It  has  been  shown  that 
in  portions  of  the  great  river  and  island  section  the  air  becomes 
extremely  dry  in  summer  by  reason  of  the  exclusion  of  water  by 
Jevees  and  pumping,  and  because  of  the  strong  west  wind  which  prevails 
all  summer,  and  that  by  reason  of  this  atmospheric  dryness  the  rust  is 
greatly  checked  and  develops  only  late  in  the  season  where  the  condition 
is  active.  Proof  has  also  been  given  of  the  fact  that  a  certain  amount  of 
dew  is  necessary  for  the  development  of  the  disease,  and  that  without 
this  or  other  moisture  on  the  asparagus  tops  no  rust  whatever  will  ever 
appear,  so  that  conditions  which  favor  the  formation  of  dew  favor  the 
rust,  and  vice  versa.  These  facts,  which  have  great  practical  impor- 
tance, are  fully  established  and  illustrated  in  the  publications 
alluded  to. 

SOIL    INFLUENCES— PHYSICAL    AND    CHEMICAL    PROPERTIES. 

Moisture.— The  relations  of  soil  moisture  to  the  rust  have  also  been 
fully  treated  in  the  above  publications.  It  has  been  shown,  both  here 
and  in  the  East,  that,  ordinarily,  asparagus  in  light,  dry  soil  is  worst 
affected  by  the  disease,  and  that  irrigation  of  such  soil  helps  decidedly 
in  controlling  the  trouble  by  giving  the  plant  more  strength  and 
resistance.  This  was  fully  demonstrated  and  illustrated  in  the  publi- 
cations mentioned,  and  is  to  be  seen  everywhere  in  our  asparagus  dis- 

xBotanical  Gazette,  loc.  cit. 


52  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT    STATION. 

tricts  where  the  soil  becomes  very  dry,  except  in  places  where  extreme 
dryness  of  the  air  checks  the  rust  to  such  an  extent  that  the  amount 
of  soil  moisture  has  no  influence. 

The  following  pages,  quoted  from  Circular  No.  9,  summarize  the 
relations  of  the  rust  problem  to  atmospheric  and  soil  moisture : 

"Natural  Conditions  Affecting  Asparagus  Rust.— It  is  gratifying  to 
announce  the  discovery  of  several  methods  by  which  the  peculiarities 
of  the  California  climate  may  be  taken  advantage  of  in  preventing  this 
disease  to  a  degree  impossible  in  any  other  asparagus-growing  State. 
This  comes  about  particularly  in  connection  with  the  dry,  rainless 
summer.  Experience  in  the  .East  has  shown  to  a  considerable  extent 
the  effects  of  moisture,  both  soil  and  atmospheric,  upon  the  develop- 
ment of  the  rust.  The  Massachusetts  Experiment  Station  early  pointed 
out  the  greater  susceptibility  to  the  disease  of  asparagus  growing  upon 
light,  sandy  loams  (the  typical  Eastern  asparagus  soil),  particularly 
in  dry  seasons,  and  recommended  planting  upon  heavier  soils,  even  if 
otherwise  not  as  well  adapted  to  asparagus,  and  also  urged  the  practice 
of  irrigation  in  dry  seasons.  A  tour  of  the  Eastern  districts  at  present, 
after  seven  years  of  rust,  will  readily  convince  one  of  the  soundness  of 
this  theory. 

"Another  idea  brought  out  was  that  heavy  dewfall  favored  the 
disease,  and  that  the  amount  of  rust  varied  with  the  amount  of  dew. 
On  account  of  the  general  occurrence  of  comparatively  heavy  dews  in 
the  East,  this  observation  has  never  been  of  much  practical  importance. 
In  this  connection  it  may  also  be  said  that  wherever  the  rust  has 
occurred  it  has  almost  always  been  noticed  that  asparagus  growing 
directly  under  the  shade  of  trees  remains  free  from  the  disease  when 
that  in  the  open  is  badly  affected.  This  had  also  been  noticed  in 
California. 

' '  In  this  State  it  is  well  known  that  great  differences  occur  as  to  sum- 
mer dews,  from  regions  where  they  are  frequent  and  heavy,  to  those 
where  there  is  absolutely  none,  a  condition  not  even  approximated  in 
the  East.  In  observing  asparagus  rust  about  the  State  the  fact  has 
been  positively  established,  that  the  amount  of  rust  varies  directly  and 
exactly  with  the  amount  of  dew,  and  that  so  long  as  there  is  little  or  no 
dew  there  can  be  no  rust.  As  applied  to  those  regions  where  practi- 
cally no  dew  whatever  occurs  in  summerj,  this  means  that  asparagus 
can  be  grown  there  with  no  danger  of  the  disease.  In  the  dry  country 
about  Fresno,  for  instance,  several  small  patches  of  asparagus  are 
growing,  free  from  rust,  while  in  a  river  bottom  near  by,  where 
moisture  is  plenty,  the  disease  is  at  its  worst.  The  same  freedom  from 
rust  occurs  in  small  asparagus  fields  in  the  Coachella  valley  near  Indio, 
while  at  Riverside  and  all  over  southwestern  California  r'ust  abounds. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  53 

It  is  not  intended  by  this  to  unreservedly  recommend  such  places  for 
asparagus  culture.  Freedom  from  rust  is  only  one  factor  of  success 
subordinate  to  many  others  which  only  experience  can  test.  Further- 
more, the  present  investigation  was  not  undertaken  to  find  new  regions 
for  asparagus,  but  to  help  those  already  in  existence.  The  above 
remarks  may,  therefore,  be  taken  for  what  they  are  worth  to  those 
interested  in  the  districts  concerned. 

"Considering  the  regions  now  devoted  to  extensive  asparagus  culture 
there  is  found  a  considerable  difference  as  to  the  amount  of  summer 
dew.  In  some  of  the  localities  adjacent  to  the  lower  end  of  San  Fran- 
cisco Bay  conditions  are  almost  as  in  the  East,  the  asparagus  tops 
being  frequently  drenched  with  dew  until  late  in  the  forenoon,  even  in 
August.  In  such  places  the  rust  becomes  abundant  on  asparagus  as 
soon  as  it  grows  up,  at  any  time  in  the  season.  This  condition  is  not 
equally  bad  in  all  the  Bay  region,  as  the  upper  portions  are  more 
exposed  to  the  trade-winds,  which  have  a  drying  effect.  Coming  to  the 
island  district,  above  the  straits  at  Port  Costa,  this  strong  west  wind 
blows  almost  steadily  during  midsummer  over  the  country  between 
Mount  Diablo  and  the  Livermore  hills  on  the  southwest,  and  the  Mon- 
tezuma hills  on  the  northeast.  It  is  strongest  and  most  constant  in  the 
range  of  Antioch,  Brentwood,  and  Sherman  and  Jersey  islands,  well 
sustained  at  Andrus  and  Bouldin  islands,  and  considerably  weaker,  but 
by  no  means  lacking,  from  upper  Grand  Island  up  t ,  Sacramento. 

"Continued  observation  has  shown  that  in  this  wind  there  is  more 
help  for  the  asparagus-growers  in  the  sections  mentioned  than  in  any 
other  one  factor  now  known.  Although  lying  so  low  as  to  require  pro- 
tection by  extensive  levees,  mostly  below  the  river  level,  these  islands 
and  adjacent  country  have  a  comparatively  dry  atmosphere  in  sum- 
mer, owing  to  the  prevailing  wind.  The  amount  of  irrigation  has,  of 
course,  an  important  local  influence,  and  this  and  the  matter  of  wind- 
breaks are  of  foremost  importance  in  respect  to  the  rust. 

"Most  of  the  existing  plantations  of  asparagus  are  just  inside  the 
levees,  heavily  irrigated,  and  sheltered  by  willows  and  bends  and  coves 
in  the  levee.  These  places  have  proven  in  almost  every  case  to  be  the 
starting  points  of  the  rust. 

"Fig.  36  shows  just  what  is  meant.  In  such  corners,  sheltered  by 
willows  on  the  west,  dew  is  quite  abundant  and  the  rust  gets  a  vigorous 
start,  often  three  or  four  weeks  before  appearing  out  in  the  open.  The 
advisability  of  avoiding  such  places  is  therefore  obvious.  The  cutting- 
down  of  all  willows  and  other  growth  forming  such  shelter  is  most 
strongly  urged.  Nothing  so  simple  and  at  the  same  time  so  effective  in 
checking  the  rust  can  be  done.  Besides  this,  all  low  spots  should  be 
avoided  in  planting  new  beds,  as  these  also  favor  dew  and  give  the  rust 
an  early  start. 


54  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT    STATION. 

/'Another  important  feature  is  seen  in  the  direction  of  the  roivs  and 
their  distance  apart.  Fields  with  rows  running  north  and  south 
(across  the  wind)  rust  considerably  sooner  on  the  sheltered,  east  side 
of  each  row  than  those  in  which  the  rows  run  with  the  wind  so  that  it 
can  blow  down  the  row  on  either  side.  For  the  same  reason  it  is 
advisable  to  plant  the  rows  ten  feet  apart  in  this  windy  country,  to 
secure  the  full  benefit.  Repeated  demonstrations  prove  conclusively 
that  by  planting  a  little  back  from  the  levee,  in  level,  open  country, 
keeping  down  all  windbreaks  and  running  the  rows  as  described,  the 
rust  can  be  held  back  at  least  a  month  in  the  river  district.  Were  it 
not  for  the  old  beds  with  their  sheltered  corners  starting  the  infection 


Fig.  36.    Corner  of  asparagus  field  in  island  district,  sheltered  on  north  and  west. 
Typical  starting-place  of  rust. 

long  before  it  would  otherwise  occur,  this  would  be  even  more  effective, 
and  growers  are  urged  to  grub  out  such  places  as  soon  as  they  become 
affected,  or,  better  than  nothing,  keep  the  tops  cut  in  summer. 

"The  matter  of  irrigation  is  also  very  important.  In  much  of  the 
river  country  water  is  applied  abundantly  and  often  excessively  all 
through  the  summer.  For  the  prevention  of  dew  and  the  resulting 
rust  the  less  irrigation  after  cutting  ceases  the  better.1  A  good  wetting 
up  to  July  first,  followed  by  thorough  cultivation  through  the  season, 
will  carry  through  any  of  this  land  and  keep  the  top  of  the  ground 
dry.  Dryness  of  the  soil  is  also  desirable  in  this  region,  in  order  to 
check  the  continual  coming  up  of  the  new  shoots,  which  goes  on  all 
through  the  fall. 

xThis  applies  only  to  the  river  district. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  55 

"Fig.  37  shows  a  method  by  which  the  rust  may  be  absolutely  pre- 
vented, but,  of  course,  is  not  applicable  to  commercial  asparagus 
growing.  This  consists  of  a  simple  cheesecloth  tent  placed  over  the 
bed  when  cutting  stops.  In  regions  of  heavy  dew  two  thicknesses  of 
the  cloth  will  be  required  to  prevent  the  rust  entirely.  The  present 
scarcity  of  healthy  asparagus  roots  for  planting  suggests  the  use  of 
such  a  method  in  seed-beds,  where  at  comparatively  small  expense 
plants  free  from  rust  could  be  easily  produced. 

' '  The  Bay  regions  where  dew  is  abundant  have  an  asparagus  soil  of  a 
sedimentary  nature,  wet  in  winter  and  usually  heavily  irrigated  in  the 
cutting  season,  but  quickly  drying  out  in  summer.  Many  of  these 
beds  are  given  little  attention  after  the  cutting  season,  and  become 


Fig.  37.    Tent  over  asparagus ;  a  rust  preventive. 

choked  with  weeds  and  extremely  dry.  Here  the  conditions  existing 
in  the  East  come  to  light.  Moisture  being  abundant  in  the  air,  heavy 
dews  are  frequent  and  remain  late  in  the  forenoon,  even  on  the  driest 
soil.  Here  are  repeated  the  conditions  which  occur  in  New  Jersey, 
eastern  Massachusetts,  and  Long  Island;  the  plants  suffer  for  water  (in 
the  soil),  while  the  rust  spores  find  an  abundance  (in  the  air).  Conse- 
quently, the  parasite  thrives  upon  the  weakness  of  the  plant.  In  every 
case  observed  in  this  district  the  wettest  beds  remained  green  the 
longest,  while  good  cultivation  helped  out  in  no  small  degree.  The 
next  figure1  shows  a  striking  case  where  the  plants  next  the  ditch  were 
green  and  vigorous  long  after  those  farther  back  were  dead  with  rust. 

"Irrigation  alone  will  not  suffice  to  save  these  beds  from  rust,  but 
will  be  of  great  assistance.  It  should  be  resorted  to,  however,  only  in 
the  district  about  Milpitas  and  Alviso,  or  wherever  the  dews  are  heavy 

*See  Circular  No.  9  and  Bot.  Gaz.  loc.  cit. 


56  UNIVERSITY    OF    CALIFORNIA— EXPERIMENT    STATION. 

all  summer  and  the  winds  uncertain.     Without  dew  no  amount  of  dry- 
ness in  the  soil  can  bring  about  rust." 

Mechanical  Structure. — The  relations  of  the  mechanical  composition 
of  the  soil  to  rust,  its  coarseness,  fineness,  heaviness,  amount  of  vege- 
table matter,  etc.,  are  largely  a  matter  of  effects  of  these  qualities  upon 
soil  moisture.  The  heavier  soils  ordinarily  retain  the  most  moisture, 
and  these4  with  other  things  equal,  produce  more  vigorous  growth  of 
asparagus  and  a  greater  degree  of  rust-resistance  than  the  lighter  and 
drier  soils.  But  naturally,  in  California,  where  we  expect  to  irrigate 
any  soil  requiring  additional  moisture,  the  nature  of  the  soil  is  con- 
sidered more  from  the  standpoint  of  asparagus  requirements,  than  of 
rust  relation.  The  fact  that  all  over  the  country  the  heavier  soils 
show  less  asparagus  rust  than  the  lighter  ones  is  due,  as  already  stated, 
to  their  greater  water-retaining  capacity,  rather  than  to  any  more 
direct  effect. 

In  the  principal  California  asparagus  districts  a  considerable  dif- 
ference in  the  effects  of  rust  on  different  soils  is  seen,  beyond  that 
connected  with  the  water  relation.  Of  the  two  principal  types  of 
asparagus  soil,  the  sediment  and  the  peat,  asparagus  in  the  latter  is 
considerably  more  damaged  by  the  same  amount  of  disease  than  on  the 
former.  This  refers  to  formations  of  pure  peat  to  a  considerable 
depth.  On  such  a  soil,  composed  almost  entirely  of  vegetable  matter 
and  water,  a  very  luxuriant,  quick-growing,  tender  and  succulent 
asparagus  is  produced,  with  straight,  white  stalks,  very  desirable  for 
canning.  But  in  such  plants  there  appears  to  be  lacking  the  element 
of  stamina  or  resistance  to  injury.  When  severely  attacked  by  rust 
the  roots  become  greatly  weakened,  and,  on  account  of  the  water-soaked 
condition  of  the  spongy  soil  in  winter,  decay  takes  place  more  readily 
and  proceeds  more  rapidly  than  in  sediment  soils,  and  the  plants  have 
less  chance  for  recovery.  It  is  also  true  that  in  the  moister  peat  soils 
new  shoots  of  asparagus  keep  coming  up  continually  until  November 
(Fig.  12),  and  the  presence  of  this  tender  young  growth  is  another 
reason  why  on  the  peat  lands  the  rust  is  more  destructive  than  else- 
where when  in  equal  abundance.  This  does  not  mean  that  there  is 
more  rust  on  the  islands  than  at  Milpitas  or  Sacramento,  for  the 
opposite  is  true,  but  that  the  same  amount  of  rust  does  greater  damage 
in  the  river  country  on  the  deep  peat  soils,  for  the  reasons  stated.  The 
moist  condition  of  the  soil,  producing  continual  new  growth  and 
quick  decay  of  affected  roots,  is  largely  to  blame,  but  there  is  also  the 
difference  in  stamina  alluded  to.  It  has  been  quite  marked  in  the 
history  of  the  rust  in  California  that  asparagus  in  the  pure  peat  soils 
of  the  San  Joaquin  side  of  the  island  district  is  more  damaged  by  one 
year's  rust  than  that  on  the  sediment  loams,  as  in  the  Milpitas  district, 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  57 

has  shown  in  three  years.  It  should  be  understood  that  this  applies  to 
soils  composed  of  peat  to  a  considerable  depth,  where  the  asparagus 
roots  reach  no  other  stratum.  Many  of  the  islands  and  reclamation 
districts,  particularly  those  reached  by  the  Sacramento  River  water, 
present  a  varied  soil  of  peat,  clay,  and  sediment  in  all  proportions  and 
various  more  or  less  definite  formations.  In  some  a  surface  layer  of 
peat  exists,  underlaid  at  no  great  depth  by  clay.  Other  localities  show 
a  more  or  less  homogeneous  mixture  of  peat  and  sediment,  while  still 
others  run  in  streaks  and  irregular  deposits  as  formed  by  the  original 
streams,  sloughs,  flood  water,  tule  and  other  growths,  and  all  the 
various  elements  which  have  been  at  work  through  the  ages  building  up 
this  remarkable  region. 

The  whole  matter  of  soil  relation  presents  itself  to  the  practical 
asparagus-grower,  and  must  of  necessity  do  so,  more  in  the  light  of 
adaptability  to  the  crop  than  of  relation  to  the  rust.  Good  canning 
asparagus,  with  the  straight,  white  stalks  which  alone  are  desirable, 
can  only  be  produced  on  soils  mechanically  adapted  to  such  growth; 
and  with  a  soil  particularly  satisfactory  in  this  respect,  even  though 
less  resistant  to  rust,  it  may  be  more  practical  to  overcome  the  disease 
in  other  ways  than  to  attempt  to  grow  the  crop  on  a  soil  not  as  well 
adapted  to  producing  good  asparagus2  even  though  with  more  rust 
resistance.  Yet,  in  the  island  country  where  large  planting  is  going 
on  or  contemplated,  much  difference  exists  in  the  rust  relation  above 
pointed  out,  on  soils  otherwise  equally  adapted  to  the  crop,  and  this 
matter   should  receive   full   consideration   under   such   circumstances. 

Chemical  Composition. — As  regards  fertility,  or  the  presence  or 
absence  of  any  particular  element  in  the  soil,  little  can  be  said  of  any 
definite  relation  to  the  occurrence  of  asparagus  rust.  It  is  true,  in  a 
general  way,  that  plants  well  nourished  and  in  vigorous  condition  are 
least  badly  affected,  yet  the  disease  sweeps  over  the  fields  with  little 
apparent  difference  in  this  respect.  Only  in  the  course  of  several 
years  of  rust  does  any  effect  of  this  sort  appear,  yet  it  is  true  that  in 
the  end  the  superior  condition  of  the  well-fertilized  beds  shows  itself 
and  proves  the  value  of  supplying  the  plant  with  all  the  nourishment 
of  which  it  can  avail  itself.  Under  California  conditions  asparagus 
is  grown  mostly  without  any  addition  of  fertilizing  material,  except 
in  some  of  the  older  districts  where  stable  manure  is  used.  With  good 
cultivation  the  production  is  very  large  from  the  natural  fertility  of 
the  soil,  so  that  there  has  been  no  incentive  to  the  use  of  fertilizers.  As 
a  rust  preventive  the  use  of  any  particular  fertilizing  substance  has 
never  shown  any  effect.  Nitrate  of  soda,  the  only  commercial  fertilizer 
used  on  asparagus  in  California,  is  certainly  valueless  in  this  respect, 
having  no  influence  on  the  occurrence  of  the  rust,  and  it  may  also  be 


58  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION. 

said  that  the  asparagus  soils  are  generally  rich  in  nitrogen  and  little 
advantage  in  the  crop  has  appeared  from  the  use  of  this  stimulant. 
Experiments  with  other  substances,  particularly  on  the  peat  lands, 
would  be  of  value,  inasmuch  as  the  productive  life  of  the  beds  might 
be  prolonged  and  the  size  and  quality  of  the  asparagus  kept  up,  even 
though  little  or  no  effect  upon  the  rust  were  obtained. 

The  old  practice  of  adding  salt  to  the  soil,  with  the  idea  of  supplying 
an  element  necessary  to  the  growth  of  asparagus,  has  frequently  been 
tried  as  a  rust  cure,  but  it  is  yet  to  be  shown  that  this  has  any  effect 
whatever  either  upon  the  growth  of  the  plant  or  the  occurrence  of  the 
disease.  Asparagus  is  capable  of  withstanding  a  large  amount  of  salt 
without  injury,  but  the  benefits  of  such  treatment  except  as  a  weed 
destroyer  are  extremely  doubtful. 

SOIL    CULTIVATION. 

Thoroughness  of  cultivation  in  asparagus-growing,  including 
broadly  all  the  operations  of  growing  the  crop,  is  of  greatest 
importance  in  handling  the  rust  problem.  This  does  not  apply  to  any 
one  method,  treatment,  or  application,  but  means  that,  in  general,  in 
any  State  and  under  any  conditions,  the  careful,  thorough  cultivator 
has  been  least  injured  by  the  rust.  So  much  is  this  true  that  the  state- 
ment is  freely  made  by  the  best  growers  in  every,  Eastern  section, 
where  the  disease  has  flourishd  for  a  number  of  years  and  practically 
exterminated  all  asparagus  beds  in  existence  prior  to  1896,  that  the 
rust  has  been  to  them  a  blessing  in  disguise  and  that  their  profits  on 
asparagus^  even  with  a  greatly  diminished  production,  are  greater  than 
ever  before.  The  difficulties  which  beset  the  growing  of  the  crop  have 
put  a  premium  on  the  product  and  the  careful  attention  necessary  to 
produce  it.  Poor  or  indifferent  growers  have  been  forced  out  of  the 
business,  the  best-taken-care-of  fields  have  survived  the  longest,  and 
their  owners,  by  taking  advantage  of  every  opportunity  to  resist  the 
destructive  pest,  have  more  than  made  up  the  direct  loss.  Clean  culti- 
vation and  good  care  of  the  crop  in  every  respect  must  be  the  basis  of 
any  rust  treatment.  Too  often  we  see  the  asparagus  fields,  after  cutting 
has  stopped,  abandoned  to  weeds,  suffering  for  water,  untouched  by 
the  plow  or  cultivator,  and  utterly  neglected  at  just  the  time  when  the 
disease  makes  its  attack  and  when  the  plant  needs  every  possible 
advantage  which  can  be  given  it. 

The  grower  who  is  looking  for  a  rust  remedy  which  will  produce 
good  asparagus  without  thorough  cultivation  and  hard  work,  will  find 
little  satisfaction  in  the  results  of  this  investigation.  The  very  fact  that 
poor  cultivation  is  common,  and  is  resulting  in  the  ruin  and  abandon- 
ment of  many  acres  of  asparagus  in  this  State,  and  will  without  doubt 
take  place  and  operate  in  the  same  way  with  much  future  planting,  is 
the  best  guarantee  of  success  for  the  better  class  of  growers. 


ASPARAGUS   AND   ASPARAGUS   RUST    IN    CALIFORNIA.  59 


THE  PREVENTION  OR  CONTROL  OF  ASPARAGUS  RUST. 

The  problem  of  rust  control  has  shown  itself  to  be  a  difficult  one  in 
other  parts  of  the  country,  and  no  less  so  in  California.  Chief  among 
these  difficulties  have  been  the  abundance,  vigor,  and  rapid  effect  of  the 
parasite,  and  the  difficulty  of  treating  the  plant  by  the  ordinary 
methods  used  for  fungous  diseases.  Added  to  this  in  California  is  the 
limited  choice  of  varieties  on  account  of  canning  quality  requirements, 
precluding  the  general  use  of  the  variety  which  is  being  most  success- 
fully grown  in  other  States.  On  the  other  hand,  it  has  been  found 
possible  to  turn  to  advantage  some  of  the  peculiarities  of  the  California 
climate  with  results  impossible  to  obtain  in  the  East,  so  that  on  the 
whole,  the  problem  has  proved  in  some  respects  a  simpler  one  here  than 
in  other  States.  It  is  also  to  be  considered  that  nowhere  has  the  sub- 
ject received  such  direct  attention  as  here,  the  enterprise  of  California 
asparagus-growers  making  it  possible  to  devote  the  writer's  almost 
entire  attention  to  this  matter  alone. 

It  should  be  understood  that  no  discovery  has  been  made  of  any 
magic  cure  for  asparagus  rust,  and  no  treatment  developed  which  will 
successfully  prevent  the  disease  without  careful  attention  to  all  the 
details  of  good  cultivation,  such  as  are  necessary  under  any  conditions. 
It  may  also  be  assumed  that  the  rust  is  here  to  stay,  that  it  will  never 
be  exterminated,  but  will  continue  its  ravages  whenever  opportunity  is 
allowed.  Asparagus  rust  is  more  abundant  in  the  State  at  the  present 
time  than  ever  before,  and  the  fact  that  methods  have  been  found  to 
control  the  disease  will  not  prevent  the  large  acreage  which  is  certain 
to  be  more  or  less  neglected,  from  becoming  rusty  each  year  until  it  is 
ruined  and  abandoned.  Such  a  result  is  already  evident  in  the  case  of 
many  fields,  and  without  doubt  much  future  planting  will  meet  the 
same  fate.  In  fact,  this  is  the  best  hope  for  the  business  in  this  State, 
for  it  is  already  evident  that,  with  a  little  encouragement  and  no  draw- 
backs, the  planting  of  asparagus  in  the  island  country  would  soon  take 
place  so  extensively  as  to  weaken  the  market  very  materially.  A 
serious  pest  which  can  be  controlled,  but  not  too  easily,  is  the  most 
effective  remedy  for  over-production. 

The  results  of  this  investigation  have  shown  that  the  rust  can  be 
controlled  in  California.  Its  occurrence  may  be  prevented  almost 
absolutely,  or  checked  to  an  extent  proportionate  to  -  the  efforts 
expended.  Theoretically,  absolute  prevention  is  most  desirable,  but 
practically  it  is  only  necessary  to  check  the  disease  sufficiently  to  pre- 
vent injury  to  the  crop,  disregarding  its  further  occurrence.  If,  for 
instance,  in  two  fields  of  asparagus,  the  one  uncared-for  becomes  rusty 
in  August  so  as  to  kill  the  tops,  while  the  other  by  proper  care  and 


60  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT    STATION. 

treatment  is  kept  green  until  November,  the  latter  may  also  become 
rusty  at  that  time  and  the  two  look  equally  bad  in  December ;  but  next 
year's  crop  will  show  the  value  of  the  treatment  and  the  needlessness 
of  attempting;  to  prevent  the  very  late  rust  occurrence,  though  an 
observer  at  that  time  might  conclude  that  the  expense  of  good  care 
and  treatment  had  been  of  no  avail.  Results  must  be  measured  by 
their  practical  value,  and  judged  and  applied  accordingly. 


PREVIOUS  ATTEMPTS  AT  ASPARAGUS  RUST  PREVENTION. 

Owing  to  the  slight  damage  caused  by  the  rust  in  Europe  no  par- 
ticular attention  has  been  paid  there  to  methods  of  prevention.  The 
only  recommendations  made  have  been  those  consisting  in  cutting  and 
burning  the  dead  tops  in  the  fall  in  order  to  destroy  the  rust  spores 
adhering  to  them.  (See  references  in  Bulletin  No.  129,  New  Jersey 
Experiment  Station.)  That  this  is  of  little  avail  in  this  country  has 
been  abundantly  shown,  and  indeed  a  knowledge  of  the  matter  shows 
that  much  more  rust  falls  unavoidably  upon  the  ground  on  the  needles 
and  small  twigs  than  can  possibly  be  destroyed  by  cutting  and  burning 
the  dead  stalks.  As  a  matter  of  culture  the  tops  are  removed  in  the 
fall,  but  this  has  little  effect  upon  the  rust  next  year. 

With  the  serious  outbreak  of  the  rust  beginning  in  1896  in  America, 
many  investigators  in  various  State  experiment  stations  became  active 
in  seeking  means  for  controlling  this  disease.  The  methods  considered 
may  be  reviewed  under  the  following  headings:  Spraying  and  simi- 
lar methods,  Cultural  methods.  Location,  Parasites,  and  Asparagus 
varieties,  each  being  of  practical  importance. 

SPRAYING   AND   SIMILAR    METHODS. 

The  prevention  of  asparagus  rust  by  spraying  the  tops  with  fungi- 
cides has  received  considerable  attention  in  the  East.  Halsted1 
reported  in  1898  the  results  of  spraying  with  Bordeaux  Mixture,  Soda 
Bordeaux,  Potash  Bordeaux,  and  Copper  Hydrate.  Beginning  June 
16,  the  plants  were  sprayed  ten  times,  at  intervals  of  one  or  two  weeks 
through  the  season.  The  cost  of  the  treatment  on  a  large  scale  was 
estimated  at  $10  per  acre  or  less.  The  result  showed  only  a  slight 
decrease  in  the  amount  of  rust  on  the  tops2  and  came  far  from  being  a 
satisfactory  treatment. 

Stone  and  Smith2  report  poor  results  from  spraying  with  Bordeaux 
mixture,  sulfid  of  potash,  permanganate  of  potash,  and  saccharate  of 
lime,  the  sulfid  of  potash  showing  the  most  effect.  The  principal 
difficulty  in  spraying  asparagus  is  mentioned  by  these  writers,  namely 

1 1'.nlletin  No.  129,  N.  J.  Expt.  Station. 
2Bulletin  No.  61,  Mass.  Hatch  Expt.  Station. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  61 

the  trouble  in  making  the  solution  stick  to  the  plant.  On  account  of 
the  smooth,  glossy  surface  of  the  needles  and  twigs  the  liquid  sprays 
collect  in  drops  and  run  off. 

Sirrine1  sought  to  overcome  this  objection  by  adding  resin  soap  to 
the  ordinary  Bordeaux  Mixture,  making  a  Resin-Bordeaux  Mixture.2 

This  mixture,  it  is  stated,  "  adhered  to  the  plants  well  and  was  not 
easily  removed  by  rains."  A  special  spraying  machine,  worked  by 
gearing  from  the  wheels  and  treating  more  than  one  row  at  once,  was 
also  devised  in  this  work.  The  results  obtained  were  encouraging, 
though  not  perfect.  The  opinion  is  stated  that  spraying  twice  a  week 
will  protect  the  young  shoots  as  they  come  up,  but  that  the  rust  will 
gradually  reduce  the  vitality  of  the  field  even  with  spraying. 

These  accounts  fairly  represent  the  results  of  Eastern  experience 
in  spraying  asparagus  with  Bordeaux  mixture  and  similar  fungicides 
in  the  years  when  the  rust  was  most  active.  Many  growers  attempted 
to  treat  their  fields  in  this  way,  but  owing  to  the  expense  of  the 
operation,  the  frequent  applications  necessary,  the  difficulty  of  covering 
the  tops  thoroughly,  and  the  poor  or  only  fair  results  at  best,  such 
treatment  was  given  up  and  most  of  the  old  beds  were  abandoned  and 
dug  out.  It  is  unnecessary  to  give  in  detail  any  further  account  of 
Eastern  experience  in  spraying,  as  this  was  the  usual  result  and  the 
practice  never  became  general  or  profitable.  The  brief  account,  by 
Chester  and  Smith3,  of  successful  treatment  in  Delaware  by  Resin- 
Bordeaux  spraying,  in  which  the  statement  is  made  that  two  sprayings, 
one  about  the  middle  of  July  and  a  second  early  in  August,  will 
prevent  injury  to  the  crop,  would  seem  to  apply  to  results  obtained 
between  1901  and  1904,  when  the  rust  showed  very  little  activity  in 
the  Atlantic  States  and  the  fields  were  almost  entirely  of  the  Palmetto 
variety.  Certainly  no  such  easy  success  can  be  obtained  ordinarily 
when  the  disease  is  active  and  unsprayed  plants  badly  affected  early 
in  the  season. 

The  only  other  treatment  by  the  application  of  any  substance  to  the 
tops,  of  which  we  have  any  record,  is  that  mentioned  in  the  fourteenth 
report  of  the  Massachusetts  Experiment  Station,  page  73,  where  Pro- 
fessor Stone  writes  as  follows :  ' '  Favorable  results  in  one  instance  were 
obtained  by  the  application  of  paris  green  to  a  young  bed.     In  this 

bulletin  188,  N.  Y.  Expt.  Station. 

2Sirrine  gives  the  following  directions  for  preparing  this  spray  : 

Resin     5  lbs. 

Potash    lye 1  lb. 

Fish    oil 1  pt. 

Water    5  gals. 

Place  the  oil  and  resin  in  the  kettle,  heating  them  until  the  resin  is  dissolved,  then 
remove  kettle  from  fire  and  allow  the  mass  to  cool  slightly,  after  which  the  solu- 
tion of  lye  is  added  slowly,  the  whole  being  stirred.  Then  boil,  adding  the  required 
amount  of  water,  until  the  solution  will  mix  with  cold  water.  Add  2  gallons  of 
this  solution  to  48  gallons  of  Bordeaux  Mixture. 
3Bulletin  63,  Del.  Expt.   Sta. 


62  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT    STATION. 

instance  a  large  bed  was  treated  twice  for  beetles  during  the  summer. 
About  August  18  the  red  stage  of  the  rust  commenced  to  show  some- 
what on  the  plants,  and  at  this  time  one  half  of  the  bed  was  treated 
with  paris  green,  early  in  the  morning,  when  the  plants  were  covered 
with  dew.  This  treatment  served  to  arrest  the  outbreak  of  the  rust 
to  quite  a  remarkable  extent."  This  observation  by  Dr.  Stone  sug- 
gests the  advantage  of  applying  copper  salts  to  asparagus  in  a  fine 
powdered,  dry  condition,  when  the  tops  are  wet  with  dew,  over  the 
liquid  method  so  difficult  to  operate  successfully.  This  idea  was  not, 
however,  followed  out  in  the  East,  until  possibly  quite  recently  in 
connection  with  the  somewhat  artificial  enthusiasm  over  ''dust  spray" 
methods.  Owing  to  the  occurrence  of  very  little  rust  in  the  seasons  of 
1902  and  1903,  and  its  late  occurrence  in  1904,  together  with  the  fact 
that  most  of  the  Eastern  fields  now  consist  of  plantings  made  since  1896 
with  a  fairly  rust-resistant  variety  of  asparagus,  spraying  was  almost 
entirely  abandoned  as  unsatisfactory,  and  to  some  extent  unnecessary. 


WORK  IN  CALIFORNIA. 

SPRAYING  EXPERIMENTS  IN   1903. 

At  the  commencement  of  this  investigation  in  the  spring  of  1903, 
work  was  started  with  the  idea  of  testing  every  possible  method  of 
treatment  which  might  prove  of  value  in  California.  The  fact  was 
quite  apparent  that  if  thoroughly  satisfactory  results  were  to  be 
obtained,  some  method  or  treatment  quite  different  from  anything 
developed  in  the  East  must  be  discovered.  Frequent  spraying  with 
any  substance  on  the  enormous  acreage  to  be  treated  was  out  of  the 
question,  even  if  the  results  were  certain  to  be  successful.  What  sug- 
gested itself  as  most  practical  for  a  spray  treatment  was  the  use  of 
something  in  a  dry,  powdered  form,  which  could  be  blown  into  the 
thick  tops  when  wet  with  dew  much  more  rapidly  and  cheaply  than 
spraying  with  a  liquid.  Liquid  sprays  were  also  tested,  in  order  to 
make  the  work  as  thorough  as  possible.  Two  typical  locations  were 
chosen  for  work :  One  in  the  region  near  Milpitas,  Santa  Clara  county, 
the  other  at  Bouldin  Island.  The  various  treatments  may  now  be 
described. 

Bordeaux  Mixture.— Mr.  John  Meads  of  Alviso  carried  out  very 
thoroughly  a  test  of  spraying  asparagus  with  this  fungicide.  The 
mixture  was  made  with  5  pounds  of  bluestone,  5  pounds  of  lime,  and 
50  gallons  of  water,  and  applied  from  barrels  in  a  wagon  with  a  Bean 
hand-power  pump  and  one  line  of  hose  (See  Fig.  38).  The  first  spray- 
ing was  made  on  July  17,  when  the  tops  were  well  up,  cutting  having 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  63 

stopped  on  July  2,  and  five  sprayings  in  all  were  made  at  intervals  of 
about  nine  days,  the  last  treatment  being  about  September  1.  One  acre 
was  sprayed,  comprising  half  of  a  small  field.  This  spraying  was  done 
with  a  constant  pressure  of  100  to  120  pounds,  giving  a  very  fine, 
misty  spray.  The  liquid  stuck  to  the  plants  fairly  well,  but  still  tended 
to*  collect  in  drops,  and  when  dry  showed  a  spotted  appearance  with 
much  of  the  plant  surface  uncovered.  About  200  gallons  of  spray 
per  acre  was  used  in  this  work  at  each  spraying,  and  two  men  with  a 
team  of  horses  required  nearly  half  a  day  to  spray  the  acre. 

The   results   obtained   were   not   encouraging.     While   a   difference 
between  sprayed  and  unsprayed  asparagus  could  be  plainly  seen  at  the 


Fig.  38.    Spraying  outfit  at  John  Meads',  Alviso. 

end  of  the  season,  still  the  best  portions  became  badly  rusted  as 
soon  as  the  disease  got  abundant,  and  the  saving  obtained  by  spraying 
was  very  slight  and  far  from  proportionate  to  the  expense  and  diffi- 
culty of  the  treatment.  The  experiment  only  confirmed  Eastern  expe- 
rience with  the  same  treatment. 

Plain  Bluest  one  Solution. — A  weak  solution  of  copper  sulfate  has 
been  found  effective  as  a  fungicide  in  some  cases,  and  being  extremely 
cheap  it  was  thought  well  to  test  this  method  of  treatment.  Mr.  George 
Nicholson  of  Alviso  sprayed  a  piece  of  asparagus  three  times,  with  a 
solution  of  1  pound  of  bluestone  to  400  gallons  of  water  the  first  two 
sprayings,  and  1  pound  to  200  gallons  the  last  time,  carrying  out  the 
operation  as  in  Mr.  Meads'  experiment. 

No  injury  to  the  asparagus  resulted  from  the  use  of  the  stronger 
solution,  but  in  regard  to  the  rust  no  effect  whatever  could  be  seen. 
The  sprayed  became  as  badly  affected  as  the  unsprayed. 


64  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

Copper  Carbonate.— A  test  of  the  ammonia-copper-carbonate  spray 
was  made  in  1903  at  Bouldin  Island,  in  cooperation  with  Mr.  Ernest 
Schultz,  of  the  Hickmott  Company.  The  spray  was  prepared  in  the 
usual  way  with  5  ounces  of  copper  carbonate,  3  pints  of  strong 
ammonia,  and  50  gallons  of  water,  making  a  paste  of  the  copper  in  a 
small  quantity  of  water,  dissolving  this  in  the  ammonia,  and  then  dilut- 
ing with  the  full  amount  of  water,  making  a  clear  blue  liquid.  The 
first  spraying  was  done  on  July  31,  before  any  rust  appeared,  and  with 
a  finely  adjusted  nozzle  and  high  pressure  the  tops  were  fairly  wel] 
covered.    The  treatment  was  repeated  several  times  during  the  season. 

Examined  on  November  24,  the  effect  of  this  spraying  was  apparent, 
and  the  results  rather  better  than  that  of  the  Bordeaux  treatment  at 
Alviso.  The  sprayed  rows  were  badly  rusted,  however,  and  in  the 
same  locality  there  is  no  reason  to  rank  this  spray  ahead  of  the  blue- 
stone-lime  combination,  since  the  rust  started  later  here  than  at  Alviso. 
In  either  case  the  saving  obtained  was  too  small  to  justify  the  frequent 
application  necessary. 

This  comprises  all  the  liquid  spraying  experiments  carried  on  in 
1903. 

DRY   POWDER   APPLICATIONS. 

Quite  extensive  tests  of  various  dry  substances  and  ^  mixtures  were 
made  during  the  first  year  of  the  work  with  the  hope  that  some  prac- 
tical treatment  of  this  nature  might  result.  This  branch  of  the  work 
was  carried  on  both  at  Milpitas  and  Bouldin  Island.  On  the  Boots 
ranch,  near  the  former  place,  the  following  powders  were  prepared: 

1  pound  Paris  Green  and  25  pounds  air-slaked  lime. 
1  pound  Copper  Acetate  and  25  pounds  air-slaked  lime. 
1  pound  Copper  Carbonate  and  25  pounds  air-slaked  lime. 
1  pound  Copper  Sulfate  and  25  pounds  air-slaked  lime. 
Powdered  sulfur. 

The  lime  mixtures  were  simply  stirred  and  churned  thoroughly 
together.  In  the  case  of  the  copper  sulfate,  the  bluestone  crystals 
were  first  heated  in  a  pan  over  a  hot  fire  and  roasted  and  crushed  until 
reduced  to  a  fine  white  powder.  The  asparagus  selected  for  treatment 
consisted  of  a  number  of  rows  in  the  midst  of  a  large  field,  going  down 
100  feet  On  each  row.  Each  mixture  was  applied  to  three  rows,  mak- 
ing fifteen  rows  altogether,  along  with  two  others  tested  in  treating 
at  different  intervals  of  time.  Thus  the  whole  experiment  took  in  100 
feet  in  length  on  seventeen  consecutive  rows,  forming  a  block  of  about 
one  quarter  acre,  nearly  in  the  center  of  a  hundred-acre  field  of 
asparagus,  and  with  other  large  fields  close  by.  The  powders  were 
put  on  at  first  with  bellows,  later  with  a  Leggett  powder-gun.  Com- 
mencing July  6  the  treatment  was  made,  except  in  the  instances  noted 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  65 

later,  once  each  week  through  the  season  until  well  into  September. 
The  work  was  done  early  in  the  morning  when  more  or  less  dew  was 
present  on  the  tops.  One  row  was  treated  twice  a  week  with  the 
bluestone  mixture,  and  another  once  in  two  weeks,  thus  making  the 
seventeen  rows. 

Bluestone.— Three  rows  were  treated  with  this  mixture  once  a  week 
all  summer,  one  row  twice  a  week,  and  one  once  in  two  weeks.  The 
first  applications  were  made  with  the  1-25  formula,  but  later  2  pounds 
of  the  copper  sulfate  were  used  with  the  25  pounds  of  lime,  with  no 
injury  to  the  asparagus  tops.  When  thoroughly  roasted  and  pulverized 
the  crystals  made  a  very  fine  powder,  mixing  perfectly  with  the 
lime  and  covering  the  tops  very  thoroughly  when  wet  with  dew.  The 
roasting  method  proved  much  superior  to  the  use  of  mechanically 
ground  or  powdered  bluestone,  the  latter  being  also  quite  expensive. 

Copper  Carbonate.— Three  rows  were  dusted  with  this  mixture  at 
the  regular  weekly  treatment.  The  commercial  carbonate  is  finely  pul- 
verized and  mixes  perfectly  with  air-slaked  lime.  The  strength  of 
1-25  was  increased  to  2-25,  as  with  the  sulfate. 

Copper  Acetate. — This  was  also  obtained  in  the  powdered  form  and 
applied  exactly  the  same  as  the  other  copper  salts,  once  a  week  through 
the  summer,  at  first  1-25  and  later  2-25. 

Paris  Green. — This  poisonous  copper- arsenic  compound  was  mixed 
with  lime  1-25  and  2-25,  and  applied  as  above. 

Sulfur.  —  The  treatment  with  sulfur  was  less  thorough  than  that 
with  the  copper  salts.  Three  rows  were  treated,  but  owing  to  the 
supply  of  sulfur  running  short  and  a  lack  of  faith  in  its  efficacy,  the 
treatment  was  discontinued  a  month  or  more  before  the  others,  making 
only  three  or  four  applications  altogether. 

RESULTS  OF  DRY  TREATMENT  IN  1903. 

Rust  developed  very  abundantly  in  this  field,  and  by  September  1 
the  tops  were  practically  dead  on  all  sides  of  the  experiment  block.  A 
difference  could  be  readily  seen  in  favor  of  the  treated  portion,  this 
block  showing  quite  green  in  the  midst  of  the  black  tops.  Examining 
the  rows  in  detail  in  October,  the  most  conspicuous  feature  was  the 
superior  condition  of  the  sulfur ed  rows.  In  these  the  uppermost  tips 
of  the  stalks  were  rusted,  and  the  more  isolated  plants,  but  the  bushy 
plants  and  all  along  the  rows  where  the  tops  were  thick  and  solid,  the 
growth  was  still  green,  with  needles  attached,  showing  a  luxuriant 
development  and  healthy  appearance.  Even  where  the  adjoining  cop- 
5— bul.  165 


66  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT   STATION. 

per  treated  raws  were  black  with  rust,  the  tops  leaning  over  and  touch- 
ing each  other,  the  sulfured  rows  were  still  green  and  healthy  in  the 
thick  growth.  Figs.  9  and  10  of  Circular  No.  9  show,  rather  poorly, 
the  comparative  condition.  The  effect  of  the  sulfur  on  the  tops  was 
noticeably  quite  the  opposite  of  that  produced  by  copper  sprays.  In 
fields  benefited  by  spraying,  the  tips  of  the  stems  and  branches  remain 
greenest  and  hold  their  needles  longest,  while  in  the  thick  bunches  of 
tops  the  rust  is  most  destructive.  In  the  sulfured  rows  the  tips  rusted 
most,  while  the  thickest  bunches  remained  greenest. 

It  is  evident  from  this,  and  a  general  knowledge  of  sulfur  action, 
that  the  effect  was  produced  by  the  fumes  of  sulfur,  rather  than  by 
direct  contact  of  the  powder.  With  copper  sprays  and  powders  the 
fungicidal  effect  is  obtained  by  a  killing  of  the  fungus  spores  from 
contact  with  the  dissolved  copper,  which  explains  the  poor  results  from 
such  treatment  of  asparagus.  The  smooth  surface  and  rapid  growth 
of  the  tops  make  it  practically  impossible  to  keep  the  needles  and 
branches  covered  with  the  liquid,  and  any  spore  not  actually  touched 
by  the  solution  is  liable  to  sprout  and  cause  infection.  Spraying  later 
will  not  affect  this  when  once  in  the  tissue,  and  we  often  see  the  rust 
pustules  breaking  out  vigorously  directly  through  a  thick  coating  of 
Bordeaux  mixture  on  the  surface.  With  sulfur,  the  powder  being 
acted  upon  by  the  hot  sun  volatilizes  into  sulfur  gas;  this  gas  per- 
meates all  through  the  tops,  comes  into  contact  with  the  germinating 
spores,  and  may  even  enter  the  breathing  pores  of  the  plant  where 
infection  is  taking  place.  In  the  thick  bunches  of  tops  where  the  rust 
finds  its  best  foothold  the  sulfur  also  is  retained  in  greatest  abundance, 
while  a  liquid  does  not  penetrate  such  places  as  readily.  When  dew  is 
abundant,  favoring  the  rust,  sulfur  is  most  easily  held  by  the  tops.  In 
the  little  sheltered  places  among  the  tops  where  rust  first  starts  the 
sulfur  gas  is  retained  more  than  in  the  open,  and  in  almost  every  way 
conditions  which  favor  the  fungus  can  be  seen,  theoretically  at  least,  to 
tend  toward  favoring  the  sulfur  treatment.  Referring  to  Figs.  21  and 
22,  on  page  31,  it  may  readily  be  imagined  how  an  abundance  of  sulfur 
:n  the  tops,  giving  off  a  gas  poisonous  to  the  germinating  spores,  would 
extend  its  influence  to  such  germinating  spores  all  through  the  tops, 
when  a  copper  spray  would  have  to  actually  touch  each  single  spore  in 
order  to  prevent  infection. 

This  was  the  theory  formed  to  account  for  the  successful  results 
of  the  sulfur  treatment.  It  may  be  said  that  not  only  on  the  original 
three  rows  was  the  effect  apparent,  but  on  the  next  rows  north  of  these, 
where  the  prevailing  wind  blew  the  sulfur  over  more  or  less  when 
applied,  green  streaks  of  foliage  could  be  clearly  seen  late  into  the 
season.     The  fact  was  unmistakable  from  every  point  of  view  that  the 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  67 

sulfur,  though  applied  less  thoroughly  than  the  other  substances,  had 
an  effect  far  superior  to  that  of  any  of  the  others. 

With  the  copper  powders  considerable  difference  in  effect  could  be 
seen,  but  none  produced  results  justifying  their  further  trial  in  prac- 
tical rust  control,  even  though  applied  so  frequently.  In  the  order 
of  effectiveness  they  ranked  as  follows:  Paris  green,  copper  acetate, 
copper  carbonate,  copper  sulfate.  The  paris  green  rows  were  notice- 
ably greener  than  those  treated  with  the  other  copper  powders,  and 
better  than  the  field  sprayed  with  Bordeaux  mixture,  thus  confirm- 
ing Professor  Stone's  observation  in  Massachusetts;  but  as  a  practical 
rust  treatment  the  results  were  not  sufficient  to  encourage  further 
trial.  The  rows  were  badly  rusted  in  spite  of  the  numerous  and  fre- 
quent applications  of  this  poisonous  substance.  Still  it  is  well  to  know 
this  fungicidal  property  of  paris  green,  in  connection  with  its  use  as 
an  insecticide.  Copper  acetate  showed  a  slight  effect,  copper  car- 
bonate very  little,  and  copper  sulfate  almost  none.  The  row  treated 
twice  a  week  with  the  latter  substance,  standing  next  north  of  the 
three  sulfured  rows  which  had  only  three  applications  during  the  whole 
season,  stood  black  and  dead  beside  the  green  of  the  more  success- 
ful treatment,  presenting  a  striking  contrast,  with  here  and  there  a 
streak  of  green  foliage  where  the  sulfur  blew  over  and  stuck  to  the 
tops. 

At  Bouldin  Island  in  1903  similar  experiments  were  tried,  testing 
the  copper  sulfate  and  copper  acetate  powders,  and  also  a  commercial 
dust  spray  put  out  by  the  Bowker  Insecticide  Company  of  Boston, 
called  by  them  "Special  Bodo,"  a  copper-lime  or  dry  Bordeaux  mix- 
ture. The  results  here  agreed  with  those  at  Milpitas,  some  saving  by 
these  copper  compounds  being  apparent,  but  not  sufficient  to  justify  the 
operation.  The  "Special  Bodo"  showed  the  best  results  and  might 
be  used  to  some  advantage  in  the  East.  Copper  acetate  showed  a  slight 
effect,  and  bluestone  scarcely  any.  All  the  rows  treated  became  badly 
rusted. 

This  comprises  all  the  spray  work  carried  on  in  1903.  From  the 
results  obtained  the  fact  seemed  plainer  than  ever  that  treatment  with 
any  liquid  was  out  of  the  question,  and  that  dust  sprays  containing 
copper  salts  as  the  active  principle  were  equally  unsatisfactory.  The 
unlooked  for  success  of  the  sulfur  treatment  gave  much  hope  of  devel- 
oping a  practical  and  effective  method  of  applying  that  substance  on  a 
large  scale.  The  fact  was  considered  as  established  that  sulfur  would 
prevent  the  rust  almost  absolutely;  if  it  could  be  applied  at  the  right 
time  and  in  the  right  way  at  not  too  great  expense  it  might  be  said 
that  a  satisfactory  method  of  rust  control  had  been  found.  Previous 
to  the  season  of  1904  the  following  letter  was  sent  to  all  asparagus- 


68  UNIVERSITY    OF    CALIFORNIA  — EXPERIMENT    STATION. 

growers  connected  with  the  investigation,  giving  the  best  information 
which  was  available  at  that  time : 

Dear  Sir  :  As  a  subscriber  to  the  fund  for  the  investigation  of  the  asparagus 
rust,  this  is  to  inform  you  more  definitely  than  was  stated  in  my  recent  circular  as 
to  what  is  most  advisable  for  the  coming  season.  While  I  shall  be  in  the  field 
all  through  the  season,  it  is  impossible  to  see  everybody  at  once  and  you  will  no 
doubt  wish  to  be  informed  in  good  season  as  to  the  best  course  to  pursue. 

In  regard  to  a  remedy  for  the  rust,  I  will  say  that  the  method  mentioned  on 
page  16  and  Figs.  9  and  10  of  the  Circular,  consists  simply  in  applying  dry  sulfur 
to  the  asparagus  tops  after  they  come  up  in  the  summer.  I  do  not  wish  to  claim 
too  much  for  this  treatment  until  it  has  been  more  thoroughly  tested,  but  give  it 
now  simply  as  being  much  more  effective  on  the  rust  than  any  other  treatment  now 
known.  It  is  also  cheap  and  easy  to  apply.  We  have  yet  to  learn  bow  many  appli- 
cations will  be  most  profitable  and  the  best  means  of  putting  on  the  sulfur.  In 
districts  which  have  been  badly  affected,  I  would  advise  the  trial  of  three  applica- 
tions, the  first  about  three  weeks  after  cutting  stops,  or  when  the  tops  are  begin- 
ning to  blossom  out  and  become  bushy,  and  the  others  at  intervals  of  two  to  four 
weeks,  according  to  conditions.  If  the  nights  are  dry,  with  little  dew  or  fog, 
there  is  no  danger  of  rust,  but  with  moisture  in  the  air  the  disease  -is  sure  to  start. 
What,  is  said  in  the  Circular  will  give  an  idea  about  this.  Sulfuring  early  in  the 
season,  when  the  sun  is  hot  (before  September  1)  seems  to  be  much  more  effective 
than  later  applications.  If  it  can  be  put  on  early  in  the  morning,  when  dew  is 
present,  it  will  stick  better  to  the  tops  and  at  the  same  time  meet  the  rust  when 
it  is  most  active.  This,  however,  will  not  be  practical  in  large  fields,  but  even  that 
which  falls  to  the  ground  is  not  wasted,  but  gives  off  the  sulfur  gas  which  circu- 
lates among  the  tops.  The  use  of  high-grade,  sublimed  sulfur  is  recommended  for 
this  work,  rather  than  the  slightly  cheaper  ground  sulfur,  which  is  sold  quite 
largely.  Arrangements  have  been  made  by  which  the  growers  of  any  section,  by 
combining  their  orders,  may  obtain  an  excellent  grade  of  sublimed  sulfur  at  a 
reasonable   rate. 

For  applying  sulfur  any  blowing  or  dusting  arrangement  may  be  used ;  the  use 
of  a  seed-sower  has  been  suggested  for  large  fields. 

In  regard  to  liquid  sprays,  I  may  say  that  I  have  followed  very  closely  all  that 
has  been  done  in  the  East  in  this  line,  as  well  as  giving  all  such  methods  a  thorough 
trial  in  this  State  last  year.  On  account  of  the  expense  of  using  such  a  method  and 
the  very  limited  success  at  best,  I  feel  convinced  that  this  is  out  of  the  question  for 
California.  The  sulfur  treatment  is  certainly  much  more  effective  and  decidedly 
cheaper  and  easier  to  apply  than  any  liquid  spray.  Still  it  is,  of  course,  only  on 
trial  and  growers  must  use  their  own  judgment  as  to  how  extensively  they  will  go 
into  it  this  year.  I  am  well  informed  as  to  the  condition  of  all  the  asparagus  in 
the  district  and  shall  be  glad  to  advise  each  grower  as  to  his  particular  case. 

I  would  especially  call  your  attention  to  what  is  said  in  the  last  paragraph  on 
page  13  of  the  Circular,  about  keeping  down  all  volunteer  growth,  etc.  The  spring 
rust  has  already  appeared  in  certain  places,  and  if  such  growth  is  allowed  to  remain 
until  the  main  fields  grow  up  great  harm  will  be  done.  Even  m  the  young  beds, 
which  are  not  cut,  it  will  be  better,  if  they  show  any  early  rust,  to  mow  them  off 
about  a  week  before  the  end  of  the  cutting  season,  burn  the  tops  and  let  every- 
thing come  up  together.  Wild,  or  volunteer  asparagus,  should  hereafter  be  looked 
upon  as  worse  than  any  weed  which  ever  grew,  and  treated  accordingly. 

WORK    AT    SACRAMENTO    IN    1904. 

For  1904  plans  were  made  to  confine  that  portion  of  the  work  which 
related  to  spraying  mostly  to  the  development  of  means  for  applying 
sulfur  cheaply  and  effectually  on  a  large  scale.  Many  growers  prepared 
to  test  the  treatment,  and  much  work  was  done  during  the  season  along 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  69 

this  line,  at  least  one  hundred  tons  of  sulfur  being  used  on  asparagus 
by  growers  who  had  supported  the  investigation.  Those  at  Sacramento 
were  the  first  to  begin,  cutting  having  stopped  there  early,  on  June  14. 
The  growers  were  alarmed  at  the  decided  effect  upon  the  quality  of 
the  crop  by  the  rust  of  the  year  before,  and  as  the  fields  there  are 
small  they  proceeded  with  great  thoroughness  and  at  considerable 
expense,  to  apply  the  methods  recommended  for  rust  control.  Some 
applied  simply  the  plain  sulfur  treatment,  while  others  tested  various 
sprays  and  combinations  according  to  their  own  or  other  ideas.  While 
naturally  some  mistakes  were  made,  and  unnecessary  or  ineffective 
operations  carried  on,  as  in  any  new  work  of  this  kind,  it  may  be  fairly 
said  that  this  work  of  the  Sacramento  growers  proved  to  be  the  most 
valuable  and  instructive  demonstration  of  spraying  for  rust  control 
that  has  ever  been  performed,  since  the  work  was  done  on  a  commercial 
scale,  numerous  methods  and  combinations  were  tried,  some  did  the 
work  more  thoroughly  than  others,  the  fields  were  close  together  and 
under  practically  the  same  conditions,  and  the  rust  was  abundant  in 
the  neighborhood.  In  this  section  the  disease  had  first  appeared  dur- 
ing the  preceding  summer  and  became  very  abundant  in  the  fall,  so 
that  before  October  1  all  the  beds  were  badly  affected  and  the  tops 
nearly  all  dead. 

In  1904  the  spring  rust  came  on  early  in  the  season  on  wild  and 
uncut  asparagus,  and  the  fungus  continued  to  develop  in  abundance  as 
the  season  progressed,  so  that  by  July  1  some  old  abandoned  beds  and 
the  wild  asparagus  which  grows  in  abundance  outside  the  levee  were 
already  yellow  and  badly  affected.  The  rust,  in  short,  wherever  it  had 
an  opportunity,  was  active  and  abundant.  Observing  this  the  growers 
began  sulfuring  very  soon  after  cutting  stopped  and  the  tops  had 
begun  to  come  up,  fearing  lest  the  disease  should  get  ahead  of  them. 
Between  June  20  and  July  1  treatment  began  on  most  of  the  beds 
which  received  any  attention. 

The  first  work  was  done  with  one  of  the  numerous  sulfur-blowing 
arrangements  in  the  market,  but  the  method  proved  somewhat  unsatis- 
factory. The  tops  were  not  yet  fully  branched  and  covered  with  foli- 
age, sulfur  would  not  stick  well,  and  scarcely  any  remained  on  the 
plants  except  when  applied  early  on  very  wet  mornings,  the  machine 
discharged  only  a  small  amount,  and  altogether  the  work  was  slow  and 
promised  to  be  ineffective.  To  get  over  a  large  field  thoroughly  and 
quickly,  working  only  a  short  time  in  the  morning,  was  quite  impos- 
sible. Some  worked  through  the  day,  but  this  was  plainly  of  little 
use,  as  scarcely  any  sulfur  remained  on  the  tops,  and  the  quantity  used 
was  scarcely  a  tenth  of  that  required  in  a  good  application.  This  treat- 
ment was  kept  up  for  some  time  in  a  few  instances,  the  small  quantity 
6— bul.  165 


70  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT   STATION. 

of  sulfur  required  appealing  strongly  to  the  economical  instincts  of  the 
Chinese  tenants,  but  the  final  results  showed  its  uselessness. 

Some  of  the  growers  then  conceived  the  idea  of  spraying  the  tops 
with  liquid,  following  with  dry  sulfur.  This  allowed  of  working  all 
day,  and  in  the  small  fields  of  that  section  was  a  feasible  operation, 
the  largest  growers  having  less  than  thirty  acres  and  most  of  them 
less  than  twenty.  Consequently  after  some  preliminary  sulfuring, 
most  of  the  beds  were  sprayed  with  Bordeaux  mixture,  followed  with 
sulfur  while  the  tops  were  wet.  The  blowing  arrangements  were  given 
up  and  the  sulfur  simply  sprinkled  on  by  hand,  after  being  run  through 
a  flour-sifter.  The  spraying  was  done  with  a  hand  pump  and  barrel, 
pulled  on  a  sled  by  one  horse  between  the  rows,  using  one  or  two  lines 
of  hose.  Other  men  followed  behind  with  buckets  of  sulfur,  sprinkling 
it  on  by  hand  as  soon  as  the  tops  were  sprayed.  This,  when  well  done, 
made  a  very  thorough  treatment  and  required  about  200  gallons  of 
spray  and  one  sack  (110  pounds)  of  sulfur  per  acre,  costing  about 
$3.50  for  materials.  The  labor  item  was  quite  heavy  where  men  had  to 
be  hired  especially  for  this  work,  as  five  men  and  a  horse  could  cover 
only  a  few  acres  per  day.  The  application  made  was  not  as  heavy  as 
this  in  all  cases,  some  growers  using  much  less  sulfur  and  putting  on 
only  one  sack  to  several  acres. 

A  second  treatment  was  started  on  most  of  the  fields  July  18  to  20. 
At  this  time  rust  was  very  abundant  on  everything  which  had  not  been 
treated,  while  all  the  beds  which  had  received  any  attention  were 
green  and  healthy.  Consequently  the  necessity  of  the  sulfur  treatment 
in  addition  to  spraying  with  bluestone  was  doubted  by  some,  and  they 
put  on  simply  the  Bordeaux  mixture.  Others,  however,  repeated  the 
full  treatment  as  described  above,  the  total  expense  being  somewhat 
greater  on  account  of  the  tops  being  larger.  On  two  places,  those  of 
Mr.  Jacob  Olsen  and  Mr.  E.  Rider,  extending  from  Sixteenth  to 
Twenty-third  streets  in  the  pocket  formed  between  the  railroad  embank- 
ment and  the  levee,  sulfur  alone  was  being  used  without  any  liquid 
spray.  On  Mr.  Olsen 's  place  the  work  was  being  carried  on  by  China- 
men during  the  owner's  absence  from  town,  with  the  result  that 
a  very  small  quantity  of  sulfur  was  used  at  first,  and  this  in  the  mid- 
dle of  the  day  when  almost  none  stayed  on  the  tops.  These  places 
were  also  surrounded  by  rusty,  wild  asparagus  on  the  embankments 
and  outside  the  levee.  Being  sheltered  from  the  wind  and  very  favor- 
able to  dew  formation,  they  were  much  the  worst  places  in  the  whole 
district. 

Mr.  Rider  began  with  a  bed  of  young  plants  not  cut,  which  were 
exposed  to  rust  the  whole  season  as  much  as  the  near-by  wild  growth. 
He  treated  this  bed  liberally  with  sulfur  throughout  the  season,  and 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  71 

the  plants  remained  green  and  made  a  good  growth  until  fall.  His 
main  beds  were  partly  planted  between  rows  of  pear  trees,  with  the 
plants  in  many  places  rather  scattering  and  not  presenting  the  thick 
solid  growth  which  is  best  adapted  to  sulfur  treatment.  Mr.  Rider 
worked  very  thoroughly,  getting  out  at  3  a.  m.  to  sulfur,  and  watch- 
ing carefully  for  any  appearance  of  rust  in  order  to  make  the  applica- 
tion especially  heavy  in  such  places.  The  O'Brien  brothers  tried  at 
the  second  treatment  a  combined  bluestone-sulfur  spray,  boiling  sulfur 
and  lime  together  and  then  adding  the  bluestone.  This  was  used  on  a 
young  bed,  not  cut,  where  considerable  spring  rust  started,  but  the  first 
spraying  and  sulfuring  seemed  to  check  its  spread,  as  the  tops  still 
looked  green  and  healthy,  while  untreated  asparagus  everywhere  was 
very  rusty. 

These  various  treatments  continued  through  the  latter  part  of  July, 
this  second  application  being  finished  by  August  1.  At  this  date  there 
was  a  little  rust  appearing  in  Mr.  Olsen's  and  Mr.  Rider's  fields, 
plainly  coming  in  from  wild  growth  near  the  edges  of  the  beds.  At  one 
place  the  writer  found  one  single  wild  rusty  stalk  on  the  inside  of  the 
levee  at  the  edge  of  the  field,  and  a  corresponding  patch  of  rust  starting 
in  the  end  of  the  row  opposite,  showing  the  importance  of  the  relation 
of  such  growth  to  the  problem  of  rust  control.  Ten  acres,  and  as  easily 
a  hundred,  started  to  rust  or  were  checked  from  rusting,  by  leaving  or 
removing  one  stalk  of  wild  growth!  One  of  the  fields  treated  with 
Bordeaux  mixture  alone  also  showed  a  few  spots  of  rust  at  this  time. 
All  the  others  were  perfectly  clean.  Those  untreated  were  black  and 
dead  where  grown  the  whole  season,  while  a  bed  cut  at  the  same  time 
as  the  treated  ones  and  situated  close  to  them  was  getting  quite  yellow 
and  rusty. 

Increasing  rust  during  the  early  part  of  August  in  the  beds  not 
sulfured  at  the  second  treatment,  while  those  which  had  received  the 
full  application  were  still  free  from  the  disease,  revived  popular  faith 
in  the  dry  substance,  and  the  spray  pump  went  out  of  use.  Some 
who  had  been  using  Bordeaux  alone  stopped  when  partly  across  the 
field  and  finished  with  sulfur  alone,  and  the  difference  in  effect  was 
quite  marked.  Most  of  the  fields  were  treated  with  sulfur  alone  about 
the  middle  of  August,  but  no  more  spraying  was  done.  Mr.  Olsen 
returned  and  applied  about  two  sacks  of  sulfur  to  the  acre  on  his  Six- 
teenth-street field  which  had  been  poorly  treated  and  showed  some  rust 
on  the  edges.  Mr.  Rider  continued  sulfuring,  especially  where  any  rust 
showed,  and  his  fields  kept  green  and  with  no  rust  of  any  consequence. 
The  first  of  September  showed  little  change  in  conditions.  The  Six- 
teenth-street field  had  considerable  rust,  though  still  looking  green 
from  the  railroad.     It  had  a  fine  growth,  with  thick  strong  tops  and 


72  UNIVERSITY    OF    CALIFORNIA— EXPERIMENT    STATION. 

numerous  berries.  Mr.  Rider's  and  the  Twenty-third-street  field  were 
green  and  fine.  Mrs.  Harding's  and  all  the  neighboring  fields  were 
green  and  perfectly  clean,  when  nearly  dead  at  the  same  time  a  year 
before.  October  15  the  Sixteenth-street  field  was  quite  badly  rusted, 
with  most  of  the  tops  dead  above  though  still  green  toward  the  bottom. 
The  tops  had  made  a  fine  growth  and  bore  ripe,  mature  berries  and 
seed.  Mr.  Rider's,  the  Twenty-third-street  place,  and  all  the  other 
fields  were  still  entirely  green  except  in  a  few  small  spots  near  the 
back  slough,  where  a  fringe  of  wild  growth  existed,  and  these  places 
were  by  no  means  bad,  but  with  patches  of  rust  in  the  upper  part  of 
some  of  the  bushes. 

The  connection  here  with  the  rust  from  the  wild  plants  was  again 
perfectly  evident,  so  many  spores  coming  continually  from  such  a 
source  that  no  treatment  could  prevent  some  infection.  By  the  last 
of  November,  1904,  the  date  of  this  writing,  the  asparagus  tops  at  Sac- 
ramento had  reached  natural  maturity  and  were  being  cut  in  prepara- 
tion for  winter  and  next  season.  In  the  Sixteenth-street  field  they  were 
nearly  dead,  with  only  a  little  green  left  at  the  bottom.  The  stalks 
were  clean  and  sound,  however,  and  not  rotted  down  into  the  ground. 
The  growth  appeared  mature  and  the  roots  uninjured,  though  much 
of  the  late  rust  which  came  in  could  have  been  held  off  by  better  atten- 
tion early  in  the  season  when  the  owner  was  away.  Mr.  Rider's  and  the 
Twenty-third-street  field  were  still  quite  green  though  rusty  on  top. 
No  indication  of  injury  was  apparent.  The  other  places  did  not  rust 
at  all  to  any  extent  except  as  already  mentioned.  The  tops  made  the 
finest  growth  for  several  years,  matured  naturally,  and  these  beds 
should  produce  normally  next  year. 

The  growers  there  seem  satisfied  that  the  rust  problem  is  solved  with 
the  sulfur  treatment,  though  some  modifications  and  new  suggestions 
can  be  made  in  the  recommendations  for  next  year.  To  the  Sacra- 
mento growers  especially  is  due  the  credit  of  taking  up  the  work 
when  in  the  experimental  stage  and  by  their  own  efforts  establishing 
many  valuable  facts  of  general  application  and  benefit. 

WORK  AT  MELPITAS  IN  1904. 

At  Milpitas  the  work  during  1904  consisted  almost  entirely  in  a 
study  and  trial  of  methods  of  applying  dry  sulfur  on  a  large  scale  and 
the  best  time  of  application.  The  fields  being  larger  here  than  at 
Sacramento,  up  to  a  hundred  acres  in  some  instances,  wholesale  methods 
are  more  necessary  and  those  covering  only  a  few  acres  per  day  are 
quite  useless.  The  fields  are  less  thickly  planted,  the  returns  per  acre 
less,  and  the  business  is  carried  on  with  Chinese  share-farmers  whose 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA. 


73 


interests  and  prejudices  must  be  more  or  less  considered.  The  district 
is  also  full  of  abandoned  beds  or  those  poorly  cultivated  and  very 
much  neglected,  wild  asparagus  lines  every  permanent  fence,  some  beds 
are  leased  outright  and  cared  for  neither  by  owner  nor  tenant  after 
cutting  stops,  climatic  conditions  are  very  favorable  to  the  rust,  and, 
all  in  all,  the  problem  here  is  the  most  difficult  of  any  place  in  the  State. 
The  success  of  the  sulfur  treatment,  as  applied  in  a  small  way  in 
1903,  convinced  all  who  saw  the  results  that  this  was  an  effective  means 
of  rust-control  in  this  section,  and  that  there  was  only  required  an 
economical  method  of  applying  the  substance  to  make  its  use  a  prac- 
tical success.     Mr.  Boots'  ingenious  mind  evolved  the  idea  of  a  modified 


Fig.  39.    Gem  seed-sower,  as  adapted  for  sulfuring  asparagus. 

seed-sower,  these  instruments  being  already  in  use  for  applying  sulfur. 
He  devised  and  had  made  the  machine  shown  in  Fig.  39.  This  con- 
sists of  an  ordinary  Gem  sower,  mounted  on  a  high-bodied,  arched- 
axled  truck,  designed  to  straddle  the  rows,  with  a  horse  in  either  fur- 
row. The  pole  is  attached  to  the  bed,  with  an  arched  neckyoke  of  iron 
pipe  in  front.  No  double-tree  is  used,  thus  leaving  an  entirely  clear 
space  for  the  asparagus  tops.  The  seed  sower  is  tipped  somewhat  at 
an  angle  to  throw  downward,  the  whole  idea  being  simply  to  clear  the 
asparagus  tops  and  not  break  them  down.  Some  growers  used  an 
ordinary  wagon  or  one  as  high  as  could  be  obtained,  but  these  injure 
the  tops  to  a  considerable  extent,  especially  where  the  rows  are  high. 
The  machine  illustrated  has  a  clear  height  of  ^ve  feet,  but  it  is  believed 
that  four  feet  would  be  sufficient.     The  hopper  holds  a  sack  of  sulfur, 


74  UNIVERSITY    OF    CALIFORNIA— EXPERIMENT   STATION. 

and  several  more  can  be  carried  on  the  platform,  counterbalancing  the 
weight  of  the  driver  and  operator,  two  men  being  required.  The 
operator  stands  at  the  rear  of  the  platform,  controlling  the  flow  of 
sulfur  by  means  of  the  levers,  and  with  a  little  practice  the  amount  to 
be  applied  per  row  or  acre  can  be  distributed  very  uniformly.  Sheets 
of  tin,  not  shown  in  the  illustration,  were  applied  above  and  at  the 
sides  of  the  outlet,  to  throw  the  sulfur  down  as  much  as  possible.  In 
practice,  this  contrivance  was  found  to  throw  out  the  sulfur  in  a  per- 
fect cloud  of  dust  (see  Fig.  40),  which  settled  down  upon  the  aspara- 
gus tops,  drifted  up  and  down  the  rows  and  through  the  thick  growth 
like  smoke.     When  wet  with  dew  the  tops  could  be  quite  thoroughly 


Fig.  40.    Seed-sower  at  work  with  sulfur. 

covered  very  rapidly.  Good  work  could  not  be  done  when  any  wind 
was  blowing,  and  after  9  a.m.  the  cloud  of  sulfur  usually  rose  high  in 
the  air,  so  that  from  every  consideration  early  morning  proved  the  best 
time  for  sulfuring.  Owing  to  delays  in  constructing  the  machine, 
work  was  not  begun  at  Milpitas  until  quite  late  in  the  summer,  when 
rust  was  already  abundant. 

Most  of  the  growers  in  that  vicinity  waited  for  a  demonstration  of. 
this  method  of  application  before  commencing  any  sulfuring,  so  that 
every  field  treated  contained  much  rust  before  anything  was  done ;  and 
most  of  them  had  very  rusty  fields  adjoining  and  were  already  badly 
rusted  on  the  adjacent  side. 

Under  such  circumstances  the  results  obtained  at  Sacramento  Were 
not  to  be  expected,  and  in  many  cases  little  if  any  advantage  resulted 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  75 

from  the  application  of  sulfur,  demonstrating  the  necessity  of  thorough 
work  early  in  the  season. 

At  the  Boots  ranch  the  first  sulfuring  was  done  on  August  8th,  the 
tops  having  grown  since  June  25.  Rust  was  quite  abundant  at  both 
ends  and  on  the  east  side  of  the  field,  coming  in  from  wild  growth  and 
an  abandoned  bed,  the  tops  being  already  quite  yellow  in  these  places. 
Through  the  body  of  the  field  the  fungus  was  lightly  distributed  but 
spreading  rapidly,  while  the  west  side,  farthest  from  the  sources  of 
infection,  was  still  clean.  The  machine  was  run  in  every  fifth  row 
(7  feet  apart),  and  putting  on  the  sulfur  at  the  rate  of  two  sacks  to 
three  acres  the  intervening  rows  could  be  covered  fairly  well.  One 
sack  per  acre  made  a  little  better  covering,  while  an  allowance  of  two 
sacks  per  acre  produced  a  tremendous  dust  cloud  and  heavy  covering 
on  the  tops.  The  amount  of  wind  and  dew  influenced  very  decidedly 
the  distribution  of  the  sulfur  and  much  of  the  finest  material  spread 
far  out  over  the  field. 

Proceeding  in  the  way  described,  on  rows  1,500  feet  long,  an  average 
of  six  acres  per  hour  could  be  easily  covered.  No  small  amount  of 
sulfur  was  doubtless  wasted,  for  although  most  of  it  found  lodgment 
somewhere  in  the  field,  that  on  the  ground  between  the  rows  was 
probably  too  far  from  the  tops  to  do  much  good.  The  farther  apart 
the  rows  the  greater  would  be  such  waste,  so  that  the  seed-sower  method 
would  be  better  adapted  to  the  closely  planted  fields  at  Sacramento, 
but  less  so  on  the  9  and  10-foot  rows  on  the  islands.  Three  mornings' 
work  of  two  men  and  a  pair  of  horses  on  the  sower,  and  one  man  and 
a  horse  to  distribute  the  sacks  of  sulfur,  sufficed  to  cover  Mr.  Boots' 
field  of  eighty  or  ninety  acres.  There  was  no  dew  at  this  time,  so  that 
the  sulfur  did  not  stick  as  well  as  might  be  desired.  After  the  opera- 
tion the  sulfur  fumes  were  very  strong  in  the  field  during  sunshine. 
Several  of  the  other  growers  proceeded  to  sulfur  their  fields  to  a 
varied  extent,  but  all  were  more  or  less  rusted  at  the  time  and  some 
quite  badly.  Most  of  the  growers  used  seed-sowers,  although  in  some 
cases  hand-shakers  were  employed.  Some  fields  were  not  treated  until 
the  middle  of  August,  when  hopelessly  rusted  already.  About  August 
20  the  Boots  field  was  sulfured  again,  but  an  unexpected  shower  on 
August  23  washed  off  most  of  the  material  and  the  work  was  repeated, 
making  three  applications  of  nearly  fifteen  tons  of  sulfur  altogether, 
on  this  field.  Others  using  more  or  less  sulfur  in  this  section  were 
Messrs.  Barber,  Cottle,  Abel,  Cropley,  Bellew,  Nicholson,  Murphy,  and 
Meads. 

The  results  of  all  of  this  work,  compared  with  that  at  Sacramento, 
showed  especially  the  necessity  of  thorough,  early  treatment,  and  that 
fields  already  considerably  rusted  can  not  be  helped  much  by  sulfuring 


76  UNIVERSITY    OP    CALIFORNIA— EXPERIMENT    STATION. 

or  any  other  treatment,  since  for  every  rust  spot  that  shows  there  are 
probably  many  thousand  infections  already  started  and  ready  to  break 
out,  whatever  fungicide  may  be  on  the  surface.  There  was  also  demon- 
strated here  in  1904  more  clearly  than  ever  the  great  importance  of 
destroying  wild  asparagus  near  the  fields  and  the  difficulty  of  any 
successful  treatment  in  close  proximity  to  abandoned,  rusty  beds. 
Every  stage  in  the  progress  of  the  disease  could  be  traced  from  such 
sources  and  those  fields  situated  farthest  from  any  other  asparagus 
were  least  rusted. 

In  regard  to  the  results  of  the  sulfur  treatment  in  this  section,  it  may 
be  said  that  all  the  fields  rusted  badly  early  in  the  fall.  It  was  quite 
evident  that  the  sulfur  retarded  the  rust  in  the  best  treated  fields,  but 
their  rusty  condition  before  the  work  started,  the  great  amount  of  rusty 
growth  all  about  them  (most  of  which  could  be  prevented),  and  the 
unusual  rain  in  August,  all  helped  to  make  the  treatment  far  from 
successful.  Most  of  the  fields  were  quite  yellow  by  September  1,  while 
those  most  neglected  were  black  and  dead.  In  those  of  Messrs.  Barber, 
Boots,  and  Cottle,  which  were  most  thoroughly  treated,  the  body  of  the 
field  was  still  green  and  the  rust  evidently  considerably  retarded  by  the 
sulfur,  but  on  the  edges  or  ends,  next  to  other  rusty  growth,  the  tops 
were  getting  quite  yellow  and  rusty.  By  the  middle  of  October  all 
untreated  fields  and  those  sulfured  when  quite  rusty  were  entirely 
dead  and  looked  very  badly.  In  the  Boots  field  the  instructive  fact 
was  noticeable  that  on  the  west  side,  where  no  rust  was  present  when 
the  first  sulfuring  was  done,  the  tops  were  still  green  and  showed  very 
little  of  the  disease,  while  the  rest  of  the  field  was  very  rusty.  In  this 
and  the  other  two  places  mentioned  the  tops  made  a  fine  growth,  con- 
siderably better  than  that  of  the  year  beforej  and  ripened  berries  and 
seeds.  They  were  certainly  better  than  any  of  the  untreated  fields 
under  similar  conditions,  although  one  or  two  small  beds  considerably 
distant  from  other  asparagus  kept  quite  green  all  the  season. 

In  the  best  treated  fields  the  distribution  of  the  sulfur  became  quite 
marked  late  in  the  season,  the  asparagus  tops  showing  green  spots  and 
streaks  in  the  rusty  portions,  where  the  sulfur  was  applied  most 
abundantly,  suggesting  that  one  heavy  application  thoroughly  and 
uniformly  made  might  be  better  than  several  light  sprinklings.  The 
results  both  at  Sacramento  and  Milpitas  indicated  most  decidedly  that 
success  in  rust  control  lay  in  keeping  out  the  disease  from  the  first  of 
the  season,  rather  than  in  destroying  it  after  once  started. 

In  the  river  district  some  work  of  an  experimental  nature  was  done 
in  1904,  particularly  at  Vorden  on  the  Van  Loben  Sels  ranch.  On  this 
place,  which  is  situated  several  miles  from  any  other  asparagus,  great 
efforts  were  made  to  check  the  rust  by  cultural  methods,  consisting  in 
the  best  of  cultivation,  keeping  down  all  willows,  weeds,   and  other 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  77 

windbreaks  along  the  ditches,  and  allowing  no  wild  asparagus  to 
develop.  Although  there  was  a  large  acreage  of  young  fields  on  the 
place,  these  had  not  rusted  in  1903  (when  this  section  was  first 
affected)  and  no  spring  rust  developed  upon  them.  Cutting  stopped 
July  2  and  the  tops  made  a  fine  healthy  growth  with  no  sign  of  rust 
throughout  the  summer.  A  supply  of  sulfur  was  laid  in,  but  not  used 
until  late  in  the  season. 

LIQUID  SPRAYING  EXPERIMENTS  IN  1904. 

Some  liquid  spraying  experiments  were  tried  at  Vorden  which 
are  worthy  of  mention.  For  this  a  portion  of  a  small  field  was  chosen 
which  had  rusted  badly  in  1903,  and  several  hundred  feet  on  two  rows 
was  sprayed  with  each  of  the  following  mixtures : 

No.  1.  No.  2. 

Caustic    Soda    10  lbs.  Bluestone    10  lbs. 

Sulfur    35  lbs.  Lime     13  lbs. 

Fish-oil  Soap   6  lbs.  Water 100  gals. 

Water 100  gals.  This  was  a  plain  Bordeaux  mixture. 

The  soda  in  No.  1  was  first  brought  to  a  boil  in  a  kettle  of  water  and 
the  sulfur  then  slowly  added  and  boiled,  with  frequent  stirring,  for 
about  an  hour,  making  a  dark  yellowish-brown  liquid  with  considerable 
sediment.  The  soap  (a  cheap,  soft,  brown  quality)  was  also  boiled  in, 
and  the  whole  made  up  to  100  gallons  for  use,  straining  the  boiled 
mixture  through  a  fine  screen  into  the  spray  tank.  In  making  this 
spray,  set  kettles  used  for  lime,  salt  and  sulfur  preparation  were 
employed. 

No.   3.  No.  k- 

Bluestone     10  lbs.  Bluestone    10  lbs. 

Lime     13  lbs.  Lime     13  lbs. 

Soap    6  lbs.  Resin    5  lbs. 

Water    100  gals.  Soap    8  lbs. 

Water 100  gals. 

No.  3  was  Bordeaux  with  fish-oil  soap  added,  first  being  dissolved  in 
hot  water  and  allowed  to  cool. 

For  the  Resin-Bordeaux  mixture  (No.  4)  the  resin  was  first  melted 
in  an  iron  pot  and  the  soft  soap  then  added  and  the  whole  heated 
and  stirred  until  well  mixed  and  quite  soft.  This  was  then  added  to 
a  kettle  of  hot  water  and  boiled  and  stirred  for  some  time  until 
thoroughly  dissolved,  which  was  not  a  difficult  operation.  The  whole 
was  then  cooled  and  added  to  the  ordinary  Bordeaux  mixture,  making 
a  decidedly  sticky  liquid. 

This  spraying  was  done  on  August  25  and  26,  using  the  outfit  shown 
in  Fig.  41.  This  consisted  of  two  100-gallon  tanks  and  a  hand  pump 
on  a  two-horse  wagon,  driving  between  the  rows.  A  hand-rail  was  put 
upon  the  rear  end  and  the  two  men  spraying  stood  by  this,  each  with 
a  short  rod  handled  in  one  hand  and  spraying  the  row  on  his  side.     One 


78  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT    STATION. 

or  two  men  pumped  and  one  drove  and  stirred.  It  was  not  found 
possible  to  drive  along  and  spray  sufficiently  without  stopping  the 
team,  but  this  arrangement  made  the  work  more  rapid  and  less 
laborious  than  spraying  from  the  ground.  About  200  gallons  per  acre 
were  required,  and  four  or  five  acres  per  day  could  be  covered  by  one 
outfit  with  the  mixtures  ready-prepared  for  them.  But  one  applica- 
tion was  made  during  the  season. 

Of  the  various  mixtures  the  Sulfur-Soda-Soap  No.  1  combination 
was  most  satisfactory  in  covering  the  tops.  This  made  a  complete, 
uniform  covering,  spreading  perfectly  over  the  glossy  surface,  with 
no  tendency  to  collect  in  drops.  The  spray  was  perfect  in  this  respect. 
No.  2,  the  plain  Bordeaux,  acted  as  usual  on  asparagus,  collecting  in 
drops  and  refusing  to  spread  smoothly  over  the  surface.     No.  3  was 


Fig.  41.    Spraying  outfit  at  Vorden  Ranch.    (Operator  holds  short  spray-rod.) 

much  better  in  this  respect,  and  No.  4  perhaps  even  more  satisfactory 
and  certainly  more  sticky  than  either.  None  of  the  copper  sprays 
made  the  perfect  surface  covering  of  No.  1.  When  dry,  the  latter 
showed  a  light  yellow  sulfur  precipitate  coating  the  well-sprayed  tops 
completely.  The  others  had  the  usual  blue  color  and  showed  the 
difference  in  composition  by  the  greater  or  less  tendency  to  form 
separate  drops. 

No  rust  appeared  in  this  section  until  after  the  rain  which  occurred 
in  September,  and  none  to  any  extent  until  further  showers  had  fallen 
in  October.  When  examined  October  132  the  main  fields  showed  scat- 
tering rust,  but  none  anywhere  of  any  extent;  simply  spots  here  and 
there  in  the  upper  part  of  the  tops.  In  the  sprayed  field  there  was  con- 
siderable rust  on  the  still  green  tops,  and  on  the  unsp rayed  portion 
quite  a  good  deal.  The  various  rows  with  different  sprays  ranked  in  this 
order:     1,  4,  3,  2,  the  first  showing  scarcely  a  trace  of  the  fungus,  the 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  79 

second  and  third  more  but  only  very  little,  while  the  plain  Bordeaux 
was  not  much  better  than  the  unsprayed.  All  the  spray  mixtures 
were  still  in  evidence  on  the  tops,  although  several  unusually  early 
rains  had  occurred  and  much  new  growth  had  taken  place.  In  the 
rows  sprayed  with  No.  1  considerable  burning  of  the  youngest  growth 
was  apparent,  and  it  was  evident  that  the  solution  could  be  made 
weaker  to  advantage.  On  November  1  there  was  a  good  deal  of  rust  on 
the  fields,  but  the  sprayed  rows  still  showed  the  same  relative  condi- 
tion. The  unsprayed  was  getting  quite  bad  and  considerable  rust  was 
coming  in  on  all  the  rows.  By  November  7  the  old  fields  were  pretty 
thoroughly  rusted  and  the  tops  being  cut.  The  younger  beds  were 
still  mostly  quite  green,  but  naturally  mature.  In  the  sprayed  field 
the  part  not  treated  was  quite  black  and  all  green  foliage  lost,  though 
the  stalks  were  still  green.  The  sprayed  rows  were  much  greener, 
with  considerable  foliage.  On  the  rows  with  No.  1,  the  liquid  sulfur, 
not  much  foliage  remained,  but  close  examination  showed  that  com- 
paratively little  rust  was  present.  Apparently  the  caustic  nature 
of  the  spray  had  caused  an  early  maturity  rather  than  the  rust.  Nos. 
3  and  4  had  the  most  foliage,  but  really  more  rust  than  No.  1.  No.  2 
was  a  little  better  than  the  unsprayed. 

A  large  amount  of  dry  sulfur  was  used  on  this  ranch  after  the  rust 
appeared,  in  September  and  October;  but  owing  to  considerable  rain 
and  a  lack  of  hot  sunshine  at  this  season,  it  is  not  probable  that  much 
saving  was  effected.  The  tops  made  a  fine  mature  growth,  and  the 
disease  coming  so  late  on  the  old  foliage  can  be  expected  to  have  had 
but  little  or  no  effect. 

The  sulfur  treatment  was  tried  to  some  extent  at  other  places  in  the 
river  section,  but  owing  to  the  late  appearance  of  the  rust  and  to 
thorough  cultural  methods  in  these  places,  no  definite  conclusions  can 
be  drawn,  and  no  injury  is  probable  from  such  an  occurrence  of  the 
disease.  At  the  Andrus  and  Grand  Island  ranches  of  the  Golden  State 
Asparagus  Company,  for  instance,  some  treatment  was  intended,  but, 
owing  to  excellent  cultivation  and  favorable  climatic  conditions,  little 
was  necessary  in  this  line,  no  rust  appearing  to  any  extent  until  very 
late,  when  the  tops  were  mature,  even  after  the  early  rains. 

This  concludes  the  general  history  of  spraying  experiments  for 
asparagus  rust  in  California,  so  far  as  they  have  been  connected  with 
this  investigation  or  publicly  reported.  Most  of  the  outside  asparagus 
has  received  no  treatment  and  has  suffered  from  rust  according  to  the 
conditions  in  the  various  districts. 


80  UNIVERSITY    OF    CALIFORNIA— EXPERIMENT   STATION. 

GENERAL  CONCLUSIONS  ON  SPRAYING  AND  SIMILAR   METHODS 

OF  TREATMENT. 

These  experiments  on  the  application  of  dry  and  liquid  sprays  to 
asparagus  have  shown  quite  plainly  the  following  facts : 

1.  That  sulfur,  either  in  dry  or  liquid  form,  acting  largely  by  its 
gaseous  fumes,  is  a  satisfactory  rust  preventive  when  properly  applied. 

2.  That  it  can  be  so  applied,  economically  and  practically,  in  any 
part  of  the  district  covered  by  the  investigation,  if  the  treatment  is 
properly  adapted  to  local  conditions. 

3.  That  all  contact  sprays,  liquid  or  powder,  fail  to  give  good  results 
on  account  of  poorly  covering  the  plant  surface,  or  because  too  frequent 
applications  are  necessary  to  keep  up  with  the  new  growth.  Of  these 
the  Resin-Bordeaux  is  the  best,  and  the  plain  Soap-Bordeaux  nearly 
as  good. 

4.  That  no  spraying  method  should  be  resorted  to  until  rust  control 
by  cultural  methods  has  been  carried  as  far  as  possible,  and  that  with- 
out reasonable  attention  to  the  latter  the  best  of  spraying  will  probably 
fail.  Of  the  various  districts,  treatment  is  most  necessary  in  those 
represented  by  Sacramento  and  Milpitas,  where  the  rust  starts  early, 
increases  all  summer,  and  much  wild  and  abandoned  growth  exists 
which  it  is  impossible  to  suppress.  In  these  places  each  grower  must 
look  out  for  himself,  and  fight  as  best  he  can  the  pestilence  which  too 
often  his  negligent  neighbor  is  fostering. 

DRY   SULFUR   TREATMENT. 

That  the  action  of  dry  sulfur  alone  on  the  tops  will  successfully 
prevent  rust,  has  been  shown  by  the  experiment  at  Milpitas  in  1903, 
the  work  at  Sacramento  in  1904,  and  to  a  less  extent  at  Milpitas  in 
1904.  That  it  will  not  do  so  unless  put  on  in  season,  in  sufficient 
amount,  and  in  such  a  way  as  to  cover  the  tops  quite  thoroughly,  has 
been  likewise  shown  in  the  same  and  other  instances.  That  it  is  most 
effective  early  in  the  season  was  shown  at  Milpitas  in  1903  and  at 
Sacramento  in  1904,  when  none  was  applied  after  the  first  of  Septem- 
ber, and  by  the  failure  of  later  applications  at  Milpitas  and  Vorden  in 
1904  to  show  much  effect.  The  conclusion  has  therefore  been  reached 
that  one  heavy,  thorough  application  in  July  would  be  most  effective 
in  the  districts  where  the  rust  spreads  rapidly  at  that  time.  Sulfuring 
after  the  first  of  September  has  shown  very  little  effect  anywhere,  so 
that  this  treatment  can  not  be  strongly  urged  at  that  time,  and  in  the 
districts  where  rust  occurs  only  after  the  date  mentioned,  other  lines  of 
treatment  must  be  looked  to  for  the  best  results.  In  places  where  the 
rust  becomes  abundant  in  July  and  August  the  dry  sulfur  has  shown 
itself  to  be  effective  when  properly  applied. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  81 

Time  for  Treatment.— The  time  of  beginning  treatment  is  one  of  the 
most  important  considerations.  This  varies,  naturally,  with  the  time 
when  cutting  stops.  At  Sacramento  in  1904  cutting  stopped  on  June 
14  and  most  growers  began  sulfuring  and  spraying  within  a  week. 
This  was  evidently  too  soon,  doing  no  harm,  of  course,  but  making 
unnecessary  labor  and  expense.  At  Milpitas  the  cannery  shut  down 
on  June  25  and  cutting  stopped  soon  after.  No  sulfuring  was  done 
until  the  first  and  second  weeks  in  August,  which  was  altogether  too 
late.  The  best  time  for  these  sections  appears  to  be  about  three  weeks 
after  cutting  stops,  before  any  rust  appears,  but  after  the  tops  get 
branched  and  "feathered  out"  a  good  deal.  This  is  about  the  time  of 
blossoming.  For  reasons  of  economy  the  work  should  not  be  done  too 
early,  and  if  the  tops  are  very  young  and  unbranched,  probably  very 
little  good  would  be  done ;  but  where  rust  is  abundant  in  the  neighbor- 
hood its  appearance  in  the  field  must  not  be  waited  for,  but  treat- 
ment applied  within  the  time  mentioned.  If  cultural  methods  prove 
successful  in  holding  off  the  disease  the  treatment  may  be  further 
postponed;  but  too  early  is  much  better  than  too  late.  With  one  good 
treatment  in  July,  and  strict  attention  to  cultural  methods  (keeping 
down  wild  growth,  etc.),  one  more  treatment  should  be  sufficient. 
This  may  be  best  applied,  judging  from  experience,  about  a  month  after 
the  first,  or  not  later  than  the  middle  of  August — not  over  a  month 
apart  at  most.  These  two  treatments  should  be  sufficient  if  properly 
made  and  supplemented  by  proper  care  in  other  particulars,  though 
judgment  must  be  used  according  to  circumstances,  and  in  small  beds 
more  attention  can  be  given  than  in  large  fields.  The  time  must  also 
be  chosen  according  to  the  amount  of  dew  present,  if  dry  sulfur  alone 
is  used.  It  is  better  to  wait  a  few  days  for  wet  mornings  than  to 
attempt  to  sulfur  dry  tops. 

Amount  of  Sulfur.— One  sack  of  finely  pulverized  sulfur  per  acre 
applied  evenly,  and  all  on  the  tops,  makes  quite  a  liberal  application, 
but  if  thrown  on  in  lumps,  wasted  on  the  ground,  or  put  on  when  the 
tops  are  dry,  little  sulfur  will  be  seen  on  the  asparagus  after  the 
application  has  been  made.  Experience  shows  that  one  heavy  applica- 
tion, after  the  tops  are  fairly  well  grown,  is  more  effective  than  two 
light  ones  a  short  time  apart,  and  it  is  believed  that  nearly  two  sacks 
per  acre,  well  applied,  the  first  time,  and  one  sack  the  second,  will  give 
the  best  results  which  can  be  obtained  from  that  amount  of  sulfur. 

Kind  of  Sulfur. — Commercial  sulfur  is  furnished  in  different  grades 
and  at  correspondingly  different  prices.  It  is  commonly  found  on  the 
market  in  the  forms  known  as  flour  of  sulfur  and  flowers  of  sulfur,  the 
former     being     ground     sulfur     and     the     latter     that     which     has 


82  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT   STATION. 

been  sublimed.*  Sublimed  sulfur  is  the  most  expensive,  finest,  light- 
est, and  purest  form.  Ground  sulfur  varies  in  fineness  and 
purity  according  to  the  care  taken  in  its  manufacture,  but 
ordinarily  contains  at  least  98  per  cent  of  sulfur,  and  may  be 
made  very  fine  by  thorough  grinding,  and  by  running  it  through 
bolting  cloth.  The  various  grades  of  sulfur  range  in  price  at  San  Fran- 
cisco from  about  $30  to  $45  per  ton.  Several  commercial  brands  are 
on  the  market.  For  asparagus  treatment  the  fineness  of  the  article 
is  the  most  important  feature.  Percentage  of  purity  is  of  no  practical 
importance,  as  any  respectable  brand  contains  at  least  97  or  98  per 
cent  of  pure  sulfur.  A  coarse,  pure  sulfur  has  much  less  value  than  a 
very  fine  article  of  less  purity.  A  small  amount  of  acidity  is  also  no 
drawback,  but  possibly  of  value  as  a  fungicide.  Asparagus-growers 
intending  to  use  sulfur  in  large  quantities  should  get  an  exact  state- 
ment or  guarantee  of  the  grade  to  be  furnished,  before  purchasing, 
and  should  know  definitely  whether  it  has  been  ground,  bolted,  or 
sublimed.  A  genuine  sublimed  or  flowers  of  sulfur  is  the  most  effective 
form  for  use  on  asparagus,  being  finer  and  lighter  than  any  other. 
Next  to  this  is  to  be  preferred  that  made  as  fine  as  possible  by  grinding 
and  bolting.  The  bulk  or  size  of  the  sack  gives  a  fair  idea  of  the 
fineness  of  the  sulfur,  a  sack  of  sublimed  sulfur  being  nearly  twice  as 
large  as  the  same  weight  of  coarsely  ground  material.  The  sublimed 
has  an  actual  value  of  several  dollars  per  ton  more  than  the  ground 
for  use  on  asparagus,  since  it  is  lighter,  sticks  better  to  the  tops, 
vaporizes  more  readily  in  the  sun,  has  greater  bulk  per  ton,  and,  in 
general,  goes  further  and  is  more  effective.  Dealers  would  do  well 
to  make  as  low  a  price  as  possible  on  sublimed  sulfur  and  encourage 
its  use.  Growers  who  consider  the  price  prohibitive  on  such  a  quality 
should  obtain  a  finely  ground  and  bolted  sulfur.  We  shall  be  glad  at 
any  time  to  examine  samples  of  sulfur  or  to  advise  as  to  its  value  and 
use,  either  for  growers  or  dealers. 

Methods  of  Applying  Dry  Sulfur.— Sulfur,  to  be  effective  in  rust 
control,  must  be  applied  in  the  form  of  a  fine,  smoke-like  dust,  reach- 
ing and  sticking  to  every  part  of  the  plant  surface.  It  does  little  good 
when  thrown  on  if  it  contains  many  large  or  small  lumps,  as  these  go 
through  to  the  ground  and  present  no  surface  to  the  sun.  It  is  also 
ineffectual  to  sprinkle  on  a  streak  here  and  there,  leaving  much  of  the 
growth  with  no  sulfur  upon  it.  If  the  tops  are  too  dry,  little  sulfur 
will  stick  firmly,  however  put  on,  and  again  the  results  will  be  poor. 
All  these  sources  of  failure  and  the  ideal  result  desired  should  be  kept 
in  mind,  whatever  method  is  followed.     The  simplest  way  of  apply- 

*In  the  trade  flowers  of  sulfur  is  distinguished  as  the  finest  grade  produced  in 
the  process   of  sublimation. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  83 

ing  sulfur  is  to  sprinkle  it  on  directly  by  hand.  If  the  material  is 
first  carefully  sifted  and  the  tops  are  quite  wet,  this  may  be  done 
fairly  well,  but  in  practice  a  great  deal  is  thrown  on  by  the  handful 
and  not  sprinkled  carefully  through  the  tops.  It  can  not  be  called  a 
very  satisfactory  method  for  general  use,  and  on  a  large  scale  is  too 
slow  if  carefully  done.  For  use  on  a  small  scale  the  method  of  appli- 
cation by  the  ordinary  pepperbox-style  hand-shaker  is  about  as  good 
as  any.  This  is  slow,  but  gets  the  sulfur  on  in  the  dusty  condition 
desired  and  enables  the  operator  to  cover  the  tops  very  thoroughly. 
Many  special  appliances  or  "dust  sprayers"  are  also  on  the  market 
for  such  work,  of  all  kinds,  sizes,  and  degrees  of  value  or  worthless- 
ness,  some  working  on  the  bellows  and  others  on  the  fan- wheel  prin- 
ciple. The  following  quite  complete  list  of  makers  of  such  machines 
is  presented  here  for  reference,  with  no  comment  on  the  merits  of  the 
individual  machines : 

Kiser  Whirlwind  Duster  Manufacturing  Co.,  Stanberry,  Mo. 

Graves  Dust  Sprayer  Co.,  Bentonville,  Ark. 

Haldeman  Manufacturing  Co.,  Springfield,  Mo. 

Dust  Sprayer  Manufacturing  Co.,  Kansas  City,  Mo. 

Willis  Dust  Sprayer  Co.,  McFall,  Mo. 

Leggett  &  Bro.,  301  Pearl  street,  N.  Y. 

S.  A.  Haseltine,  Springfield,  Mo. 

California  Bellows  Manufacturing  Co.,  77  Federal  St.,  San  Francisco. 

Of  these  the  bellows  made  by  the  California  Bellows  Co.,  and  the 
Leggett  powder-gun,  were  purchased  and  used  in  the  work  of  1903. 
In  1904  samples  of  the  Graves  and  Haseltine  machines  were  furnished 
by  their  makers  for  trial  and  found  well  adapted  for  use  to  the  limit 
of  their  capacity.  In  large  fields  any  of  the  smaller  hand  machines 
are  too  slow.  For  heavier  work  several  of  these  firms  make  larger 
machines  running  by  a  crank  handle  and  fan-wheel  blower.  A  still 
larger  form  is  that  made  by  the  Dust  Sprayer  Manufacturing  Co., 
shown  in  Fig.  42,  running  by  gasoline  engine  power  in  a  walnut  grove. 

The  seed-sower  device  is  the  only  other  arrangement  known  to  the 
writer  by  which  sulfur  can  be  applied  on  a  large  scale.  Of  the  larger 
devices  it  sends  out  the  sulfur  in  the  best  shape.  Comparing  Fig.  40  on 
page  74,  with  Fig.  42,  it  may  be  seen  how  the  sower  sends  out  a  uniform 
cloud  of  dust,  settling  on  the  tops  and  drifting  all  through  them,  while 
the  blower  shoots  out  a  solid  stream,  not  spreading  until  it  has  gone 
some  distance,  passing  through  and  beyond  the  row  aimed  at,  and  tend- 
ing to  go  off  in  the  air  rather  than  stay  where  it  is  wanted.  The  seed- 
sower  also  treats  several  rows  at  once,  but  is  open  to  the  objection  that 
the  row  on  which  the  machine  is  working  gets  more  sulfur  than  the 
others,  some  of  the  intervening  rows  are  apt  to  be  poorly  done,  and 


84 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 


much  sulfur  goes  on  the  ground.  It  works  better  the  nearer  the  rows 
are  together,  and  is  scarcely  practical  where  they  are  eight  or  ten  feet 
apart.  Careless  operators  are  also  apt  to  try  to  treat  too  many  rows 
at  once  and  leave  some  which  get  very  little  sulfur.  Every  row  and 
all  the  tops  in  every  row  must  be  covered  thoroughly  for  good  results. 
In  thickly  planted  fields  the  seed-sower  will  do  this  better  and  more 
rapidly  than  anything  else.  Where  the  rows  are  far  apart  it  will  not. 
The  larger  hand-power  fan-wheel  machines  seem  best  adapted  for  the 
thorough  treatment  of  one  row  at  a  time.  Two  may  be  put  on  a  wagon 
driving  between  the  rows,   and  thus   double  work  performed.     Such 


Fig.  42.    Dust-sprayer  in  walnut  grove,  Rivera,  Cal. 

machines  are  the  Leggett  " Jumbo,' '  the  Kiser  " Whirlwind, 
man  "Tornado,"  and  Dust  Sprayer  Co.'s  "Cyclone." 


Halde- 


Cost  of  Dry  Sulfur  Treatment.— Estimating  sulfur  at  2  cents  per 
pound,  the  two  applications  described  would  cost  about  $5  or  $6  per 
acre  for  materials  during  the  season.  With  the  seed-sower  the  labor 
item  is  very  small,  only  a  few  cents  per  acre.  Hand  work  is  more 
expensive. 

LIQUID  SPRAYING. 

The  value  of  liquid  spraying  has  been  found  to  be  in  two  directions : 
its  direct  action  in  suppressing  the  rust,  and  its  aid  to  the  sulfur  treat- 
ment in  sticking  on  the  sulfur  independent  of  dew.  In  the  former 
respect  the  liquid  sulfur  has  shown  the  best  results,  while  for  the 
latter  purpose  it  is  also   most   desirable   on   account   of  wetting  the 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  85 

surface  most  thoroughly.  The  Soap  Bordeaux  is  more  easily  prepared, 
and  effective  enough  to  merit  some  consideration.  The  sulfur  spray 
combines  the  action  of  a  liquid  fungicide  with  the  gaseous  effect  of 
dry  sulfur,  since  the  sulfur  goes  on  in  a  liquid  state  as  dissolved  sulfur 
or  sulfids,  killing  any  germinating  spores  with  which  it  comes  into 
contact,  then  as  it  dries  the  sulfur  or  sulfids  crystallize  out  and  form 
a  solid  coating  with  the  soap  on  the  surface,  giving  off  sulfur  gas  when 
acted  upon  by  the  sun.  Spraying  with  this  substance  seems  to  be 
without  doubt  the  most  effective  single  treatment  for  the  rust.  Its 
practical  application,  however,  for  large  fields,  is  not  economical  unless 
it  can  be  put  on  rapidly  on  a  large  scale.  The  composition  or  propor- 
tions of  this  spray  may  be  improved  upon  by  future  experience,  but 
the  principle  of  its  action,  both  contact  and  gaseous,  has  plainly 
shown  its  superiority  to  that  of  simple  contact  sprays  like  the  copper 
mixtures,  while  its  adhesive  and  spreading  properties  surpass  those  of 
any  other  mixture  of  this  sort  known  to  the  writer.  Bluestone  should 
not  be  added  to  this  mixture,  or  any  substance  which  would  materially 
change  its  general  composition  of  sulfur  dissolved  in  a  caustic  hydrate. 
Caustic  potash  might  be  as  good  as  the  soda,  but  has  not  been  tried  in 
this  work.  There  are  a  number  of  sulfur  sprays  in  use  for  various 
purposes,  many  of  which  will  be  tried  on  asparagus  as  soon  as  possible. 
It  is  to  be  presumed  that  another  season's  experience  will  add  much 
information  in  this  connection  as  to  the  most  effective  and  economical 
sulfur  spray  which  can  be  used.  The  general  idea  in  any  case  must 
be  to  coat  the  tops  with  sulfur  or  alkaline  sulfids  in  considerable 
concentration. 

Time  for  Spraying. — What  has  been  said  in  regard  to  the  time  for 
dry  sulfur  treatment  applies  equally  well  for  liquid  spraying,  especially 
as  the  latter  is  intended  mostly  for  use  in  conjunction  with  the 
former.  The  idea  should  be  in  any  case  to  make  the  principal  treat- 
ment just  before  the  rust  usually  appears.  If  the  liquid  sulfur  spray 
is  the  only  application  made,  and  it  appears  to  be  the  most  effective 
of  any  single  treatment,  the  tops  should  be  well  sprayed  in  places  with 
conditions  like  Milpitas  and  Sacramento  at  the  time  recommended  for 
the  first  dry  sulfur  treatment  or  a  few  days  later,  when  the  tops  have 
considerable  growth  but  before  any  rust  shows  in  the  field.  At  least 
one  more  spraying  should  then  be  made,  with  or  without  dry  sulfur, 
and  for  very  thorough  work  in  places  much  subject  to  rust,  par- 
ticularly in  small  fields,  several  sprayings  will  be  found  useful. 

In  the  river  section  where  no  rust  appears  before  September  or 

October  in  open  fields,  and  the  dry  sulfur  is  less  effective  on  account 

of  the  lateness  of  the  season  and  the  width  apart  of  the  rows,  one 

spraying  with  liquid  sulfur  about  the  first  week  in  September  will  be 

7— bul.  165 


86  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT    STATION. 

found  very  effective  in  keeping  the  tops  green  late  into  the  fall,  if  this 
is  considered  necessary,  though  present  conditions  indicate  that  by 
judgment  in  planting  and  attention  to  cultural  precautions  the  rust  can 
be  held  off  late  enough  in  the  fall,  in  most  of  this  region,  to  prevent 
any  damage  to  the  crop  and  make  spray  treatment  unnecessary.  The 
time  for  any  treatment  must  be  guided  entirely  by  local  conditions 
and  previous  experience,  the  general  idea  being  to  start  just  ahead 
of  the  probable  rust  appearance  and  keep  ahead  of  it  until  late  in  the 
season. 

Methods  of  Applying  Liquid  Sprays.— The  chief  objections  to  this 
style  of  treatment  have  been,  as  previously  stated,  the  difficulty  of 
making  the  liquid  cover  the  plant  surface  thoroughly,  the  frequent 
applications  necessary  on  account  of  the  growth  of  the  asparagus  tops, 
the  slowness  of  the  work  and  large  labor  expense,  and  the  difficulty 
involved  in  transporting  such  large  quantities  of  water  about  the 
field.  The  first  objection  is  overcome  by  the  use  of  the  liquid  sulfur; 
the  second  partially  so  by  the  gaseous  effect  of  the  same  spray  after 
drying,  and  almost  entirely  so  in  the  island  country  by  the  late  appear- 
ance of  the  disease.  When  dry  sulfur  also  is  used,  the  necessity 
of  frequent  applications  is  entirely  done  away  with.  The  last  two 
difficulties  mentioned  apply  mostly  to  large  fields,  and  can  only  be 
overcome  by  the  development  of  spray  machinery  which  would  permit 
rapid  work  on  a  large  scale.  In  small  or  medium  sized  fields,  up  to 
thirty  acres,  ordinary  hand-pump  appliances  may  be  used.  For  beds 
of  a  few  acres  the  Sacramento  method  of  a  one-horse  sled  carrying  a 
barrel  and  pump  between  the  rows,  with  two  lines  of  hose,  is  quite 
satisfactory.  A  two-horse  wagon  with  two  tanks  or  barrels  and  the 
largest  size  hand-pump  is  the  next  largest  outfit.  The  method  shown 
in  Fig.  41  and  described  on  page  78  is  the  most  rapid  for  this  style 
of  work  and  has  proved  a  great  improvement  over  that  of  Fig.  38,  on 
page  63.  The  sprayers  ride  on  the  wagon  and  readily  reach  all  over  the 
row.  But  even  at  best  these  methods  allow  of  spraying  only  a  few  acres 
per  day,  and  are  too  slow  and  costly  for  fields  of  one  or  several  hun- 
dred acres.  To  meet  this  difficulty  several  machines  have  been  devised 
for  more  rapid  asparagus  spraying,  treating  more  than  one  row  at  once, 
and  pumping  by  power  obtained  from  the  wheels.  The  first  machine  of 
this  kind  was  that  described  by  Sirrine,  and  called  by  him  the  "  Downs 
Power  Asparagus  Sprayer."  This  consisted  of  a  250-gallon  half- 
round  tank,  mounted  on  a  four-wheeled  truck  high  enough  to  straddle 
a  row,  a  pump  worke)d  by  a  chain  on  one  wheel,  and  a  rather 
complicated  combination  of  piping,  carrying  twenty  nozzles,  so  located 
and  adjusted  as  to  spray  both  sides  of  the  row  straddled,  and  one 
side  of  each  of  the  adjoining  rows,  or  the   equivalent  of  two  rows 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  87 

altogether,  as  the  machine  was  driven  along  through  the  field.  Tele- 
scope and  shear  joints  in  the  piping  allowed  of  adjustment  to  rows 
of  different  widths  and  plants  of  different  height.  One  acre  per  hour 
could  be  sprayed  by  two  men  and  two  horses,  with  considerable  less 
material  than  is  used  in  hand  spraying.  The  cost  of  building  the 
machine  was  estimated  at  about  $200. 

Figure  43  shows  another  wheel  chain-power  sprayer  for  asparagus— 
that  made  by  the  Aspinwall  Manufacturing  Co.  of  Jackson,  Michigan. 
This  is  a  two-wheeled  machine  carrying  two  barrels  of  liquid,  with 
twelve  nozzles  for  the  two  rows,  connected  with  rubber  hose. 


Fig.  43.    Aspinwall  asparagus  sprayer. 

Various  other  wheel  power  machines  are  made  for  spraying,  some 
of  which  might  be  adapted  to  asparagus. 

The  chief  objection  to  all  such  arrangements  is  that  spraying  goes 
on  only  when  the  horses  are  moving  steadily,  so  that  at  the  ends  of  the 
rows  and  anywhere  that  a  stop  is  made  considerable  asparagus  is  left 
unsprayed,  while  the  pressure  often  runs  down  if  the  team  slows  a  little. 
The  sprocket  chain  on  the  wheel  for  working  the  pump  is  also  some 
extra  strain  on  the  team  if  a  high  pressure  is  maintained.  With  these 
objections  the  Aspinwall  machine,  the  only  power  sprayer  for  aspar- 
agus on  the  market  known  to  the  writer,  appears  to  be  capable  of  effect- 
ive use  in  competent  hands  and  with  a  good  spray  mixture.  Like  the 
seed-sower  for  dry  sulfur,  it  permits  a  rapid  but  incomplete  and  non- 
effective treatment  of  large  areas  when  carelessly  used  by  those  not 
realizing   or   considering   the   primary   object   of   the   work   and   the 


88  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT   STATION. 

necessity  of  treating  every  portion  of  the  growth  as  thoroughly  as  in 
hand  work. 

The  common  use  of  gasoline  engines  for  spray  power  in  California 
suggests  such  an  outfit  as  best  adapted  for  asparagus  spraying  on  a 
Jarge  scale,  and,  in  fact,  such  power  has  been  used  in  spraying  aspar- 
agus, both  East  and  West.  While  no  machine  of  this  sort  has  actually 
been  tried  in  the  asparagus  rust  investigation,  considerable  thought  has 
been  given  to  the  subject,  and  general  ideas  worked  out,  particularly  in 
connection  with  Mr.  Fred  Bromage  of  the  Vorden  Ranch,  for  such  a 
device.  An  outfit  of  this  kind  would  probably  find  use  only  in  the 
larger  fields  of  the  river  section.  <H,ere  the  tops  make  a  very  thick, 
large  growth,  and  the  rust,  appearing  only  in  September  or  later, 
starts  on  the  upper  part  of  the  tops  and  works  down.  The  sides  and 
under  part  of  the  growth  do  not  rust  until  the  top  is  gone,  being 
shaded  and  kept  dry.  This  feature  has  been  illustrated  in  Circular 
No.  9  and  elsewhere.  For  the  one  late  spraying  which  at  most  'is 
necessary  in  the  Sacramento  River  district,  a  good  covering  of  the 
upper  part  of  the  rows  is  therefore  sufficient.  For  this  purpose  there 
is  no  apparent  difficulty  in  attaching  a  cross  pipe  at  the  rear  of  the 
spray  truck  long  enough  to  cover  two  rows  (the  truck  running  between 
them),  and  put  in  this  pipe  a  number  of  nipples  to  cover  rows  at 
different  distances  apart,  though  as  a  fact  almost  all  on  the  same 
ranch  are  nearly  the  same  and  none  vary  a  great  deal.  On  the  nipple 
over  each  of  the  rows  can  be  attached  a  yoke-shaped  pipe  with  three 
or  more  nozzles  covering  the  row,  arranged  as  may  prove  most 
effective.  The  cross  pipe  may  be  made  adjustable  in  height  by  means 
of  a  supporting  frame  and  two  or  more  connections  from  the  pump. 
This  is  a  mere  suggestion,  but  it  is  expected  that  such  a  device  will  be 
actually  constructed  and  tasted  next  year.  For  rapid  spraying  of 
large  fields  there  is  practically  no  doubt  that  some  such  contrivance 
can  be  developed  for  asparagus,  along  the  lines  of  several  different 
sprayers  now  in  the  market  for  treating  several  rows  at  a  time.  For 
effective  liquid  spraying  of  much  extent  the  spray  outfit  should  be  kept 
supplied  with  the  spray  mixture  by  a  feed  wagon,  with  help  enough  to 
prepare  the  spray  and  take  it  to  the  field  as  fast  as  used. 

Cost  of  Liquid  Spray.— The  cost  of  materials  for  the  various  mix- 
tures considered  may  be  reckoned  per  acre  as  follows,  allowing  200 
gallons  of  spray: 

Liquid  Sulfur. 

12  lbs.  Caustic  Soda  at  8  cents ^0.96 

50  lbs.  Sulfur  at  2  cents 1.00 

10  lbs.  Soap  at  6  cents -0° 

$2.56 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  89 

Resin  Bordeaux. 

20  lbs.  Bluestone,   at  6y2    cents .$1.10 

25  lbs.  Lime,  at  1  cent 25 

10  lbs.  Resin,  at  4  cents 40 

12  lbs.  Soap,   at  6  cents 72 

$2.47 
Soap  Bordeaux. 

20  lbs.  Bluestone,  at  5%  cents $1.10 

25  lbs.  Lime,  at  1  cent 25 

10  lbs.  Soap,   at  6  cents 60 

$1.95 

The  best  proportions  for  these  sprays,  particularly  the  first,  have 
not  been  fully  established,  but  in  any  case  it  will  be  seen  that  the 
cost  for  materials  is  "quite  inconsiderable.  In  power  spraying  the  200 
gallons  would  cover  somewhat  more  than  an  acre,  while  with  hand 
work  a  little  more  than  that  quantity  per  acre  might  be  required.  The 
labor  item  in  all  spray  work  is  the  chief  expense.  Counting  labor  and 
materials,  asparagus  can  not  be  sprayed  with  liquid  by  hand  for  much 
less  than  $5  per  acre  at  each  application.  With  a  power  outfit  a  con- 
siderable saving  over  this  is  to  be  looked  for,  so  that  one  applica- 
tion per  season  would  not  be  impracticable  on  account  of  the  expense. 

CULTURAL  METHODS  AND  LOCATION  IN  RELATION  TO  RUST  CONTROL. 

That  in  the  ordinary  culture  of  asparagus  much  may  be  done  toward 
rust  control  in  California  has  been  frequently  alluded  to.  The  facts 
upon  which  this  rests  may  be  gathered  from  the  preceding  chapters 
pertaining  to  the  nature  of  the  rust  fungus,  its  development  and  life 
history.  The  quotation  from  Circular  No.  9  on  page  52  covers  a  por- 
tion of  this  subject  as  related  to  the  planting  and  surroundings  of  the 
fields.  The  importance  of  what  is  said  there  grows  more  and  more 
apparent  in  the  island  country  as  the  rust  increases.  Planting  the  rows 
with  the  wind,  on  level,  wind-exposed  ground  not  sheltered  by  levee 
or  trees,  and  keeping  down  all  growth  of  weeds  and  other  shelter  about 
the  fields,  needs  no  further  exposition  to  those  familiar  with  the  condi- 
tions. Asparagus  planting  in  this  section,  in  places  sheltered  on  the 
west  and  north,  incurs  needless  danger  and  expense  except  where  other 
considerations  are  more  important.  The  beneficial  effects  in  rust  con- 
trol simply  of  good  cultivation,  keeping  down  weeds,  stirring  the 
ground,  sufficient  irrigation,  etc.,  are  also  brought  out  in  Circular 
No.  9  and  are  known  to  every  grower  of  experience  with  rust.  The 
condition  of  neglected  beds  is  amply  sufficient  to  show  this. 

Coming  more  particularly  to  methods  concerning  the  development 
of  the  rust  fungus  itself,  nothing  can  be  more  apparent  than  the 
great  opportunity  of  checking  its  development  during  the  cutting  sea- 
son, when  the  main  fields  have  no  growth  above  ground.     It  has  been 


90  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

fchown  that,  from  all  experience  in  this  State,  the  rust  fungus  must  grow 
on  living  asparagus  tops  during  the  spring  and  early  summer,  and 
spreads  thence  to  the  main  fields  after  they  grow  up,  and  that  the 
further  such  growth  is  kept  from  the  fields  the  later  the  rust  will 
appear,  the  longer  time  the  tops  will  have  to  develop  naturally,  and 
the  less  spraying  will  be  necessary.  With  this  fact  established,  and 
every  observant  grower  knows  it  to  be  so,  the  simple  matter  of  keeping 
down  wild  growth  near  the  beds  need  require  no  further  mention.  It 
is  far,  and  above  all,  the  most  important  rust-preventive  method  in 
California,  in  proportion  to  the  effort  required.  Destroy  or  keep  down, 
by  all  means,  every  stalk  of  wild  asparagus  that  can  be  gotten  at.  Dig 
it  out,  cut  it  down,  pour  crude  vitriol  on  the  roots,  or  anything  to 
prevent  its  growth  before  the  fields  grow  up.  One  stalk  may  easily 
start  rust  in  a  whole  field,  so  that  the  watch  for  such  growth  can  not 
be  too  close,  especially  about  the  edges  of  the  fields.  In  young  beds  not 
old  enough  for  cutting,  growth  must  be  allowed  the  whole  season,  and 
this  is  often  a  source  of  infection.  Something  can  be  done  here,  how- 
ever, by  cultural  methods.  Infection  comes,  as  has  been  shown,  from 
spores  on  the  surface  of  the  ground  on  last  year's  needles  and  twigs, 
sprouting  in  early  spring  and  infecting  the  new  asparagus  stems. 
Burning  last  year 's  tops  destroys  some  of  these  spores,  but  by  no  means 
all,  those  on  the  finer  growth  falling  to  the  ground  (Figs.  25  and 
26  on  page  39). 

Cultivation  in  winter  or  fall  and  early  spring  will  bury  much  of  this 
material  and  lessen  infection,  so  that  in  young  beds  the  soil  should  be 
stirred  and  cultivated  as  much  as  possible  after  the  tops  are  cut  and 
when  they  come  up  again  in  spring.  The  cutting  of  young  beds,  even 
for  a  very  short  season  as  soon  as  they  are  old  enough,  is  also  con- 
ducive to  preventing  spring  rust  infection,  but  the  leaving  of  such 
beds  uncultivated  on  account  of  their  non-productive  condition  is  the 
surest  way  to  favor  the  rust.  The  matter  of  old  abandoned  beds  or 
those  not  taken  care  of  by  their  owners  is  perhaps  the  hardest  feature 
to  contend  with  in  districts  like  Milpitas  and  Sacramento.  Many  fields 
in  these  sections  are  practically  continuous,  being  separated  only  by 
fences,  and  too  often  the  disease  comes  into  a  well-taken-care-of  field  in 
overwhelming  abundance  on  the  edge  next  a  neighboring  breeding- 
place  of  rust,  and  the  owner  is  powerless  to  prevent  the  occurrence. 
Whether  county  legislation  could  or  does  cover  such  cases  seems  the 
only  possible  remedy  to  consider  after  moral  suasion  fails,  but  com- 
pulsory treatment  by  spray  methods  would  probably  be  carelessly 
done  and  without  effect,  so  that  the  only  action  of  any  probable  value 
would  be  to  require  the  total  destruction  of  all  rusty  asparagus  tops 
existing  on  a  certain  date,  say  June  1,  on  complaint  of  neighboring 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  91 

growers,  and  this  again  would  probably  be  attended  with  much 
difficulty. 

Fields  which  are  thus  exposed  to  infection  from  sources  which 
the  owners  can  not  be  persuaded  to  destroy  or  prevent,  can  only  be 
treated  by  taking  special  pains  to  prevent  any  infection  from  the 
other  sides  and  concentrating  the  efforts  of  spraying,  etc.,  on  the  most 
exposed  part.  By  early  and  very  thorough  treatment  rust  has  been 
shown  to  be  preventable  in  very  bad  places.  This  disposes  of  all  the 
possible  sources  of  spring  rust.  The  inference  is  not  intended  that  the 
occurrence  of  the  disease  can  be  prevented  altogether  in  this  way,  but 
simply  that  it  may  be  kept  at  a  distance  until  later  in  the  season  and 
much  of  the  injurious  effects  and  expense  of  treatment  prevented. 

The  matter  of  burning  the  tops  in  the  fall  needs  little  consideration, 
as  this  is  general  practice.  Cutting  and  burning  the  rusty  tops  in 
summer,  early  enough  to  force  a  new  growth,  was  at  first  tried  in  the 
East,  but  as  the  second  growth  rusts  as  badly  as  the  first  more  harm 
than  good  is  sure  to  result.  At  the  end  of  the  season  it  is  better  to  cut 
the  rusty  stalks  while  the  stems  are  still  green  at  the  bottom,  as  when 
perfectly  dead  from  rust  they  decay  down  into  the  ground  and  eat 
out  the  crowns  more  rapidly.  (See  Figs.  29  and  30,  on  page  43.) 
Other  details  of  ordinary  matters  of  cultivation  most  favorable  to  pro- 
ducing good  growth  will  suggest  themselves  to  the  practical  asparagus- 
grower,  the  aim  being  to  bring  out  here  more  especially  the  adaptation 
of  cultural  practices  to  the  life  history  of  the  fungus  and  hinder  its 
development  by  such  practical  means. 

location. 

Parties  considering  the  growing  of  asparagus  on  a  large  scale  may 
with  much  profit  consider  the  relation  of  various  localities  and 
climatic  and  other  natural  conditions  to  the  rust  problem,  as  well  as 
in  regard  to  the  general  requirements  of  asparagus  production,  though 
of  course  freedom  from  rust  is  only  one  factor  in  profitable  asparagus 
growing. 

RUST  PARASITES. 

That  the  rust-producing  organism,  itself  a  parasitic  fungus,  should 
in  turn  be  attacked  in  a  similar  manner  seems  remarkable,  but  is 
nevertheless  quite  true.  The  earlier  Eastern  publications  describe 
several  parasitic  fungi  which  live  upon  the  asparagus  rust.  Of  these 
the  most  abundant,  Darluca  filum  Cast.,  described  and  figured  by 
Halsted,  and  by  Stone  and  Smith,  and  mentioned  by  most  writers  on 
asparagus  rust,  is  a  small  fungus  developing  upon  the  rust  pustules, 
checking  their  development  somewhat,  but  living  more  upon  the  myce- 
lium than  upon  the  spores  of  the  rust.     This  fungus  has  been  abundant 


92 


UNIVERSITY    OF    CALIFORNIA  — EXPERIMENT    STATION. 


everywhere  that  rust  has  occurred  since  1896  and  is  often  to  be  found 
in  this  State,  but  its  effects  have  nowhere  been  apparent  in  reducing 
or  checking  the  spread  of  the  disease.  The  other  parasite  mentioned 
by  Halsted,  Tubercularia  persicina  Ditt.,  is  not  as  common  and  of  no 
apparent  practical  importance.  Various  mold  fungi  may  often  be 
found  on  rusty  asparagus  in  damp  weather,  especially  in  California, 


Fig.  44.    Parasite  on  rust  (C ladosporium  sp.). 

but  these  again  have  little  effect  on  the  spores  and  can  not  be  con- 
sidered of  importance  in  practical  rust  control. 

There  occurs  very  abundantly  in  California  a  rust  parasite  which 
has  not  been  previously  recorded,  or  seen  by  the  writer  in  the  Eastern 
States.  This  becomes  very  abundant  in  sections  like  Milpitas  where 
the  rust  starts  early,  and  from  all  appearances  has  quite  a  decided 
effect  in  checking  the  spread  of  the  disease  later  in  the  season.  In 
this  district,   and  more   or  less  so  in  others,  when  a  plant  or  field 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA. 


93 


becomes  covered  with  red  rust  pustules,   a  darker  brown,   mold-like 
growth   develops  on  the   rust   spots   themselves,   never   on   the   plant 


Pig.  45.    a.  Rust  spores  with  parasite,    b.  Spore  production  of  parasitic  Cladosporium. 
c.  Dead  rust  spores  with  parasitic  fungus  sprouting  from  them. 

so  long  as  it  remains  green,  and  the  rust  becomes  completely  covered 
with  this  growth.  This  is  shown  in  Fig.  44  on  the  stalks  at  the  left, 
where  the  rust  blisters  are  seen  to  be  covered  with  the  other  fungus. 


94  UNIVERSITY   OF    CALIFORNIA— EXPERIMENT   STATION. 

The  whole  field,  when  badly  rusted,  becomes  full  of  this  mold  and 
its  spores  make  a  dust  cloud  more  profuse  than  that  coming  from  the 
rust  itself.  Fig.  45a  shows  the  condition  of  rust  uredospores  attacked 
by  this  parasite,  the  latter  fungus  growing  into  and  through  almost 
every  spore  on  badly  rusted  plants  and  destroying  their  vitality.  A 
peculiar  feature  is  that  shown  in  Fig.  45c,  where  dead  spores  of  the 
rust  which  contain  the  parasite  spread  in  the  wind  in  the  ordinary 
manner,  but  send  out  sprouts  of  the  parasite  instead  of  reproducing 
the  rust.  This  is  a  form  of  Cladosporium,  and  shows  no  structural 
difference  from  the  ordinary  Clad,  herbarium  Link.,  a  very  indefinite 
species.  (Thumen  describes  Clad,  aecidiicolum  as  a  parasite  on 
various  secidia.  Zopf,  "Die  Pilze,"  p.  272.)  Fig.  455  shows  the 
spore  formation.  "What  seems  to  be  the  same  fungus  is  seen  abun- 
dantly on  dead  mustard  stalks,  but  much  less  on  any  other  plant.  It 
is  certainly  a  very  abundant  mold.  That  this  parasite  is  instrumental 
in  checking  the  spread  of  the  rust  at  Milpitas  and  wherever  it 
starts  early  appears  from  the  fact  that  the  disease  spreads  but  little 
in  such  places  after  September,  but  the  fields,  by  new  growth  which 
does  not  rust,  are  often  actually  greener  in  October  than  in  September. 
The  abundant  wild  growth,  which  is  killed  down  by  rust  in  mid- 
summer, also  comes  up  again  more  or  less  and  shows  little  rust 
thereafter^.  Certainly  the  disease  stops  spreading  in  September  or 
October  where  it  has  been  very  abundant  earlier,  and  spares  what  little 
growth  remains  or  comes  up  new,  while  the  late-appearing  rust  in 
the  islands  spreads  rapidly  in  November.  There  is  every  indication 
that  in  sections  like  Milpitas,  if  the  rust  can  be  controlled  well  into 
September  its  occurrence  thereafter  will  be  greatly  checked  by  this 
parasite. 

VARIETIES  OF  ASPARAGUS. 

There  is  no  question  that  some  varieties  of  asparagus  are  more 
resistant  to  rust  than  others.  This  difference  appears  much  more  in 
new  beds,  planted  after  the  rust  outbreak  started,  than  in  those  which 
existed  at  the  time.  So  much  is  this  true  that  in  the  East  the  rust 
problem  seems  well-nigh  solved  by  the  growing  of  Palmetto  asparagus, 
yet  in  the  first  years  of  rust  the  difference  in  favor  of  this  variety 
was  slight  and  often  not  at  all  apparent.  In  1900  Sirrine1  wrote  that 
"The  fields  on  Long  Island  have  been  watched  every  year  since  1896, 
with  the  result  that  only  slight,  if  any,  differences  in  favor  of  the 
Palmetto  were  to  be  noticed,  except  that  in  some  cases  it  did  not  suc- 
cumb as  early";  yet  at  present  in  the  same  fields  the  Palmetto  alone 
remains  and  is  being  extensively  planted.  Mr.  Wm.  Conover  planted 
a  field  on  his  place  in  New  Jersey  with  three  rows  of  Palmetto,  then 

bulletin  188,  N.  Y.  (Geneva)  Agr.  Expt.  Station,  1900. 


ASPARAGUS  AND   ASPARAGUS   RUST   IN    CALIFORNIA.  95 

three  rows  of  Conover's  Colossal,  alternately,  and  after  a  few  years 
the  Palmetto  was  still  green  when  the  other  variety  was  practically 
exterminated  so  that  those  rows  had  to  be  replanted  with  Palmetto. 
There  is  no  doubt  whatever  that  this  variety  is  much  less  affected  and 
less  injured  by  rust  in  the  long  run,  even  though  it  does  not  always 
appear  at  first.  The  Argenteuil  (Bonvallet's  Giant,  French  and  other 
trade  names)  is,  if  not  identical  with  Palmetto,  indistinguishable  from 
it,  and  equally  rust  proof.  Among  all  the  American  varieties  no  great 
difference  exists,  and  they  are  in  fact  probably  all  selections  from  the 
old  Conover's  Colossal.  All  the  older  California  fields  were  of  this 
variety,  but  by  a  long  succession  of  generations,  taking  seed  from  the 
old  beds  to  plant  new  ones,  variations  have  come  in  and  multiplied, 
until  now  the  fields  at  Sacramento  and  Milpitas  contain  numberless 
varieties  or  forms,  varying  in  color  from  white,  through  shades  of 
green,  yellow,  and  red,  to  deep  greens  and  purples,  and  also  varying 
in  size  and  shape.  Most  of  it  has  the  general  Conover  characteris- 
tics of  uniform-sized  stalks,  tender  texture,  good  flavor,  and  easy 
blanching  qualities,  and  the  Palmetto  type  is  very  little  seen,  though 
typical  Barr's  Mammoth,  Columbian  White,  and  almost  any  other 
variety  can  be  easily  found.  The  last  two  varieties  named  together 
with  Moore's  Cross  Bred,  Donald's  Elmira,  and  the  host  of  various 
seedsmen's  "Mammoth,"  "Colossal,"  and  "Giant"  varieties  are 
probably  all  selections  from  the  Conover.  The  canners  are  opposed  to 
Palmetto  on  account  of  its  color  and  coarseness,  and  the  Conover  is 
certainly  a  much  superior  canning  variety.  For  marketing  fresh  aspar- 
agus, Palmetto  is  as  good  or  better,  having  larger  stalks,  though  less 
production  and  poorer  quality. 

In  a  rusty  field  of  any  variety  plants  can  be  seen  here  and  there 
which  are  greener,  less  affected,  and  more  nearly  rust  proof  than  the 
average  of  the  field.  A  beginning  has  been  made  by  the  writer  toward 
breeding  desirable  rust-proof  varieties  by  saving  seed  of  such  plants 
from  various  States,  which  is  being  carefully  planted  for  such  a  pur- 
pose. Quite  a  collection  is  already  on  hand  from  promising  sources. 
Seed  has  also  been  imported  from  Europe  of  a  number  of  varieties 
grown  there  and  plants  have  been  obtained  from  all  of  these.  Variety 
names,  however,  outside  of  the  few  standard  kinds,  mean  very  little  in 
asparagus,  as  there  are  many  duplicates  or  kinds  indistinguishable 
from  one  another.  The  canning  requirements  have  most  to  be  consid- 
ered in  this  State,  together  with  productiveness,  as  well  as  rust  relation. 
The  Conover  is  at  present  the  best  and  only  desirable  canning  variety, 
and  may  be  groAvn,  it  is  believe^,  by  thorough  methods  of  rust  sup- 
pression, but  a  more  resistant  kin  of  equal  quality  would  be  extremely 
desirable  and  is  by  no  means  impossible. 

Circular  No.   9  contains  further  remarks  on  the  various  varieties. 


96 


UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION. 


INSECTS  AFFECTING  THE  ASPARAGUS  PLANT. 

In  connection  with  the  consideration  of  asparagus  rust  brief  men- 
tion must  be  made  of  insect  pests  which  attack  the  same  plant,  inas- 
much as  their  effects  may  be  confused  with  those  of  the  rust. 

Asparagus  Beetle. — This  is  a  small,  lively  beetle,  about  one-quarter 
inch  in  length,  which  is  getting  quite  abundant  in  California  and  may 
be  expected  to  increase  and  become  a  serious  pest  within  a  few  years.  It 

seems  to  have  arrived  in  the 
State  at  about  the  same  time  as 
the  rust,  or  at  any  rate  was  not 
noticed  by  the  growers  until 
then.  The  species  is  probably 
identical  with  the  usual  Crio- 
ceris  asparagi  L.,  although 
seeming  to  vary  somewhat  from 
the  Eastern  form.  Specimens 
have  not  as  yet  been  submitted 
to  the  Entomological  division 
of  the  Station  for  determina- 
tion. The  attacks  of  this  insect 
are  most  frequently  seen  on 
seed-beds  and  young  fields, 
where  both  the  adult  beetles  and 
the  grubs,  or  young  form,  feed 
on  the  shoots  as  they  come  up, 
and  cause  serious  damage. 
Fig.  46  shows  the  beetles,  grubs 
or  larvae,  and  eggs,  and  the 
effect  on  the  asparagus. 

The  grubs  may  be  controlled 
by  dusting  with  air-slaked  lime 
when  the  dew  is  on,  while  both 
stages  succumb  to  paris  green, 
mixed  with  lime,  flour,  or 
water.  Growers  should  be  on  the  watch  for  this  insect,  as  it  is  quite 
likely  to  become  troublesome  and  abundant  in  California. 

Asparagus  Miner  (Agromyza  simplex  Loew).— This  is  another 
Eastern  asparagus  insect  which  is  becoming  abundant  in  California, 
though  not  of  any  great  importance.  Its  effects  are  seen  at  the  base 
of  the  mature  stalks,  near  the  ground,  where  the  very  small  grubs 
burrow  a  broad,  winding  passage  just  beneath  the  epidermis,  giving 
it    a  slightly    sunken    appearance.     In    these  burrows    may    be    seen 


Fig.  46.    Asparagus  beetle  Crioceris  asparagi. 
Chittenden,  U.  S.  D.  A.  Year  Book,  1896. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  97 

through  the  epidermis  near  the  base  of  the  stalk,  small,  black,  seed- 
like bodies,  which  are  the  puparia  or  winter  stage  of  the  insect.  From 
these  emerges  in  spring  the  adult  insect,  a  small  fly.  The  miner  is 
quite  common  in  this  State,  but  causes  no  appreciable  damage.  (Sir- 
rine1  has  called  attention  to  this  insect.) 

The  Onion  Thrips. — This  very  minute  insect,  which  produces  the 
whitened,  blasted  appearance  on  green  onion  stalks,  has  been  observed 
attacking  young  asparagus  plants  in  a  similar  way  quite  severely 
where  onions  were  grown  between  the  rows.  Should  this  commonly 
occur,  the  planting  of  this  crop  in  young  asparagus  fields  should  be 
discouraged.    The  writer  has  observed  thus  far  but  one  case  of  this  kind. 

Wireworms. — Fig.  31,  on  page  44,  shows  an  effect  quite  often  seen  on 
asparagus  in  this  State,  the  work  of  young  wireworms.  These  are  very 
small,  lively  worms,  about  one-eighth  inch  long  and  hair-like  in  thick- 
ness, which  live  in  the  soil,  especially  when  moist  and  undisturbed. 
They  attack  the  tender  asparagus  shoots,  eating  out  "shot-holes"  in  the 
sides  and  making  them  tough,  unsightly,  and  worthless.  These  worms 
are  especially  troublesome  where  stable  manure  has  been  used  in  the 
row,  and  for  this  reason  some  growers  have  been  obliged  to  abandon 
the  use  of  such  material.  In  other  cases  they  occur  where  the  ground 
is  wet  and  soggy. 

A  remedy  for  this  trouble  is  found  in  avoiding  or  improving  the 
conditions  which  favor  it.  The  Sacramento  practice  of  plowing  down 
the  ridges  in  winter  and  putting  on  a  layer  of  river  sand  keeps  the 
ground  sweet  and  free  from  these  worms,  as  well  as  renewing  the 
soil.  When  the  effects  are  seen  during  the  cutting  season  the  rows 
should  be  pulled  down  as  much  as  possible  with  rakes  or  hooks,  a 
dressing  of  air-slaked  lime  sprinkled  on  the  surface,  and  the  ground 
kept  as  dry  as  possible  by  frequent  stirring. 

LIST  OF  SUBSCRIBERS  TO  FUND  FOR  ASPARAGUS  RUST  INVESTIGATION. 

California    Fruit    Canners'    Association,    J.   W.   Meads,   Alviso. 

San  Francisco.  Geo.    Nicholson,    Alviso. 

Hickmott  Asparagus   Canning  Company,    W.   Zanker,   Alviso. 

San  Francisco.  Fred  Cottle,  San  Jose. 
Golden    State   Asparagus    Company,    San    John   I.   O'Toole,    San   Jose. 

Francisco.  Andrea  Malavos  Co.,  San  Jose. 

Wm.  Boots  Estate,  Milpitas.  It.   D.   Fox,   San  Jose. 

R.  S.  Barber,  Milpitas.  F.   H.   Burke,    San   Jose. 

George   Murphy,   Milpitas.  F.  Gubbay,  San  Jose. 

Henry  Abel,  Milpitas.  Richard  Haley,  San  Jose. 

Richards    Bros.,    Milpitas.  Bruce  Brackett,   San  Jose. 

M.   Bellew,  Milpitas.  L.    Scatena   &   Co.,    San   Francisco. 

M.   A.   Farney,  Alviso.  Jacobs  &  Malcolm,   San  Francisco. 

bulletin  189,  N.  Y.  Expt.  Sta. 


98  UNIVERSITY    OF    CALIFORNIA— EXPERIMENT   STATION. 

LIST  OF  SUBSCRIBERS  TO  FUND  FOR  ASPARAGUS  RUST  INVESTIGATION— Cont'd. 

Trobock  &  Bergen,  San  Francisco.  Goetjen   &   Metsen,    San   Francisco. 

American    Produce    Co.,    San    Francisco.  Meek  Estate,  Hay  wards. 

Minaker  &  Welbanks,  San  Francisco.  G.   Oulton,   Twitchell   Island. 

McDonough    &   Runyon,    San    Francisco.  Voorman  Estate,  Bouldin  Island. 

A.  Galli  Fruit  Co.,  San  Francisco.  P.  J.  Van  Loben  Sels,  Vorden. 

Eveleth    Nash    Co.,    San    Francisco.  Jacob   Olsen,    Sacramento. 

Gray   &  Barbieri   Co.,    San  Francisco.  E.   Rider,   Sacramento. 

A.   Levy  &  Co.,    San  Francisco.  M.  M.  Harding,  Sacramento. 

John  Demartini,   San  Francisco.  O'Brien  Bros.,  Sacramento. 

Quadros,    Corries    &    Smith,    San    Fran-  Giusto  &  Son,  Sacramento. 

cisco.  E.    Condrey,    Sacramento. 

Growers'       Cooperative      Agency,       San  C.    Girolami,    Sacramento. 

Francisco.  C.   Lagarmarsino,   Sacramento. 


DIRECTIONS  FOR  ASPARAGUS  RUST  CONTROL. 

Consider  location,  soil,  and  manner  of  planting  in  relation  to  rust, 
m  planting  new  fields. 

Plant  Conover's  Colossal  for  canning,  Palmetto  for  the  fresh 
asparagus  market. 

Cultivate,  irrigate  if  necessary,  and  in  every  way  take  the  best 
possible  care  of  all  beds  throughout  the  year. 

Allow  no  asparagus  to  run  wild,  and  destroy,  or  at  least  keep  cut 
down  up  to  July  1,  all  wild  growth. 

Apply  the  same  rule  to  abandoned  fields. 

Cut  and  burn  all  tops  in  the  fall.  In  young  beds  not  cut  for  market 
cultivate  or  stir  the  soil  as  much  as  possible  after  cutting  the  tops,  and 
in  early  spring.  Do  not  let  the  new  growth  come  up  through  surface 
soil  undisturbed  since  fall. 

In  sections  where  rust  starts  early  (Milpitas,  Sacramento,  etc.) 
apply  from  150  to  200  pounds  of  sulfur  per  acre  about  three  weeks 
after  cutting  stops,  before  any  rust  shows.  Put  it  on  in  the  most 
convenient  way  of  those  described,  but  with  the  greatest  attention  to 
thoroughness  and  proper  results. 

Sulfur  only  in  the  early  morning,  stopping  not  later  than  9  a.  m., 
and  choose  only  mornings  when  heavy  dew  is  present.  The  sulfur 
must  show  on  the  tops  wherever  it  is  to  prevent  rust. 

If  thought  preferable,  spray  the  tops  with  liquid  and  dry  sulfur  for 
very  thorough  work.  If  Bordeaux  mixture  is  used  in  wetting  the 
tops  for  sulfuring,  add  soap  to  the  mixture  as  explained  in  this 
bulletin. 

About  the  middle  of  August  give  a  second  application  as  before,  or 
with  100  pounds  of  sulfur  per  acre. 


ASPARAGUS   AND   ASPARAGUS   RUST   IN    CALIFORNIA.  99 

In  regions  where  rust  holds  off  until  September  or  October  (Vorden, 
Grand  Island,  Andrus  Island,  etc.)  pay  strictest  attention  to  the  cul- 
tural methods  of  treatment  described. 

If  further  treatment  seems  necessary,  spray  once  about  the  first  week 
of  September  with  power  outfits,  using  the  liquid  sulfur  formula  as 
given  on  page  77,  prepared  as  on  page  88. 

If  young  beds  become  rusty  before  July  1  in  spite  of  cultural  meth- 
ods, cut  and  burn  all  the  tops  and  stir  the  ground  thoroughly  about 
two  weeks  before  the  old  fields  stop  cutting.    . 

Treatment  after  the  rust  appears  will  do  little  good  anywhere. 

Note. — Since  the  announcement  of  the  forthcoming  appearance  of  this  bulletin, 
numerous  inquiries  have  been  received  from  various  parts  of  the  country  in  regard 
to  the  application  in  Eastern  States  of  the  methods  found  successful  in  California. 
It  should  be  understood  that  most  of  what  is  said  in  this  bulletin  applies  only  to 
California  conditions,  with  no  rainfall  in  ordinary  seasons  from  May  to  October. 
The  use  of  the  liquid  sulfur  spray  suggests  itself  as  being  most  promising  for 
Eastern  application,  spraying  about  three  times  in  the  season,  the  first  early  in 
July  and  the  others  at  intervals  of  three  weeks.  An  outfit  like  that  in  Fig.  41  would 
be  sufficient  in  most  Eastern  fields,  or  power  sprayers  may  be  employed.  Dry  sulfur 
can  not  be  expected  to  show  much  effect  in  any  but  a  rainless  climate. 


STATION  PUBLICATIONS  AVAILABLE  FOR  DISTRIBUTION. 


REPORTS. 


1896.  Report   of   the    Viticultural    Work    during   the   seasons    1887-93,    with   data 

regarding  the  Vintages  of  1894-95. 

1897.  Resistant   Vines,   their   Selection,   Adaptation,   and   Grafting.     Appendix  to 

Viticultural  Report  for  1896. 

1898.  Partial  Report  of  Work  of  Agricultural  Experiment  Station  for  the  years 

1895-96  and  1896-97. 
1900.     Report  of  the  Agricultural  Experiment  Station  for  the  year  1897-98. 

1902.  Report  of  the  Agricultural  Experiment  Station  for  1898-1901. 

1903.  Report  of  the  Agricultural  Experiment  Station  for  1901-1903. 

1904.  Twenty-second  Report  of  Agricultural  Experiment  Station,  1903-1904. 

BULLETINS. 

Reprint.  Endurance  of  Drought  in  Soils  of  the  Arid  Region. 

No.  129.  Report  of  the  Condition  of  Olive  Culture  in  California. 

131.  The  Phylloxera  of  the  Vine. 

132.  Feeding   of   Farm   Animals. 

133.  Tolerance  of  Alkali  by  Various  Cultures. 
135.  The  Potato-Worm  in  California. 

137.  Pickling  Ripe  and  Green  Olives. 

138.  Citrus   Fruit   Culture. 

139.  Orange  and  Lemon  Rot. 

140.  Lands  of  the  Colorado  Delta  in  Salton  Basin,  and  Supplement. 

141.  Deciduous  Fruits  at  Paso  Robles. 

142.  Grasshoppers  in  California. 

143.  California  Peach-Tree  Borer. 

144.  The  Peach-Worm. 

145.  The  Red  Spider  of  Citrus  Trees. 

146.  New  Methods  of  Grafting  and   Budding  Vines. 

147.  Culture   Work  of  the   Substations. 

148.  Resistant   Vines   and   their    Hybrids. 

149.  California   Sugar  Industry. 

150.  The  Value  of  Oak  Leaves  for  Forage. 

151.  Arsenical   Insecticides. 

152.  Fumigation   Dosage. 

153.  Spraying  with  Distillates. 

154.  Sulfur   Sprays  for  Red  Spider. 

155.  Directions  for  Spraying  for  the  Codling-Moth. 

156.  Fowl   Cholera. 

157.  Commercial  Fertilizers. 

158.  California  Olive  Oil ;  its  Manufacture. 

159.  Contribution  to  the  Study  of  Fermentation. 

160.  The  Hop  Aphis. 

161.  Tuberculosis  in  Fowls. 

162.  Commercial   Fertilizers. 

163.  Pear   Scab. 

164.  Poultry  Feeding  and  Proprietary  Foods. 

CIRCULARS. 

No.  1.  Texas   Fever.  No.  8.  Laboratory     Method     of     Water 

2.  Blackleg.  Analysis 

3.  Hog    Cholera.  9.  Asparagus  Rust. 

4.  Anthrax.  10.  Reading     Course     in     Economic 

5.  Contagious    Abortion    in  Cows.  Entomology. 

6.  Methods   of  Physical   and  Chem-         11.  Fumigation    Practice. 

ical   Soil  Analysis.  12.     Silk  Culture. 

7.  Remedies   for   Insects. 

Copies  may  be  had  by  application  to  the  Director  of  the  Experiment 
Station,  Berkeley,  California. 


